M. Erdmann

We present a combined fit of a simple astrophysical model of UHECR sources to both the energy spectrum and mass composition data measured by the Pierre Auger Observatory. The fit has been performed for energies above $5 \cdot 10^{18}$ eV, i.e.~the region of the all-particle spectrum above the so-called "ankle" feature. The astrophysical model we adopted consists of identical sources uniformly distributed in a comoving volume, where nuclei are accelerated through a rigidity-dependent mechanism. The fit results suggest sources characterized by relatively low maximum injection energies, hard spectra and heavy chemical composition. We also show that uncertainties about physical quantities relevant to UHECR propagation and shower development have a non-negligible impact on the fit results.

We present the simulation framework CRPropa version 3 designed for efficient development of astrophysical predictions for ultra-high energy particles. Users can assemble modules of the most relevant propagation effects in galactic and extragalactic space, include their own physics modules with new features, and receive on output primary and secondary cosmic messengers including nuclei, neutrinos and photons. In extension to the propagation physics contained in a previous CRPropa version, the new version facilitates high-performance computing and comprises new physical features such as an interface for galactic propagation using lensing techniques, an improved photonuclear interaction calculation, and propagation in time dependent environments to take into account cosmic evolution effects in anisotropy studies and variable sources. First applications using highlighted features are presented as well.

A new analysis of the dataset from the Pierre Auger Observatory provides evidence for anisotropy in the arrival directions of ultra-high-energy cosmic rays on an intermediate angular scale, which is indicative of excess arrivals from strong, nearby sources. The data consist of 5514 events above 20 EeV with zenith angles up to 80 deg recorded before 2017 April 30. Sky models have been created for two distinct populations of extragalactic gamma-ray emitters: active galactic nuclei from the second catalog of hard Fermi-LAT sources (2FHL) and starburst galaxies from a sample that was examined with Fermi-LAT. Flux-limited samples, which include all types of galaxies from the Swift-BAT and 2MASS surveys, have been investigated for comparison. The sky model of cosmic-ray density constructed using each catalog has two free parameters, the fraction of events correlating with astrophysical objects and an angular scale characterizing the clustering of cosmic rays around extragalactic sources. A maximum-likelihood ratio test is used to evaluate the best values of these parameters and to quantify the strength of each model by contrast with isotropy. It is found that the starburst model fits the data better than the hypothesis of isotropy with a statistical significance of 4.0 sigma, the highest value of the test statistic being for energies above 39 EeV. The three alternative models are favored against isotropy with 2.7-3.2 sigma significance. The origin of the indicated deviation from isotropy is examined and prospects for more sensitive future studies are discussed.

Simulations of particle showers in calorimeters are computationally time-consuming, as they have to reproduce both energy depositions and their considerable fluctuations. A new approach to ultra-fast simulations is generative models where all calorimeter energy depositions are generated simultaneously. We use GEANT4 simulations of an electron beam impinging on a multi-layer electromagnetic calorimeter for adversarial training of a generator network and a critic network guided by the Wasserstein distance. The generator is constrained during the training such that the generated showers show the expected dependency on the initial energy and the impact position. It produces realistic calorimeter energy depositions, fluctuations and correlations which we demonstrate in distributions of typical calorimeter observables. In most aspects, we observe that generated calorimeter showers reach the level of showers as simulated with the GEANT4 program.

A measurement of the proton structure function F2 (x, Q2) is presented with about 1000 neutral current deep inelastic scattering events for Bjorken x in the range x ⋍ 10−2 – 10−4 and Q2 > 5 GeV2. The measurement is based on an integrated luminosity of 22.5 nb−1 recorded by the H1 detector in the first year of HERA operation. The structure function F2 (x, Q2) shows a significant rise with decreasing x.

The proton and deuteron structure functions F2p and F2d are measured in inelastic muon scattering with an average beam energy of 470 GeV. The data were taken at Fermilab experiment E665 during 1991 and 1992 using liquid hydrogen and deuterium targets. The F2 measurements are reported in the range 0.0008<x<0.6 and 0.2<Q2<75 GeV2. These are the first precise measurements of F2 in the low x and Q2 range of the data. In the high x range of the data where they overlap in x and Q2 with the measurements from NMC, the two measurements are in agreement. The E665 data also overlap in x with the DESY HERA data, and there is a smooth connection in Q2 between the two data sets. At high Q2 the E665 measurements are consistent with QCD-evolved leading twist structure function models. The data are qualitatively described by structure function models incorporating the hadronic nature of the photon at low Q2. The Q2 and the W dependence of the data measure the transition in the nature of the photon between a pointlike probe at high Q2 and a hadronic object at low Q2.Received 9 February 1996DOI:https://doi.org/10.1103/PhysRevD.54.3006©1996 American Physical Society

A new measurement of the proton structure function F2 (x, Q2) is reported for momentum transfers squared Q2 between ].5 GeV2 and 5000 GeV2 and for Bjorken x between 3 · 10−5 and 0.32 using data collected by the HERA experiment H1 in 1994. The data represent an increase in statistics by a factor of ten with respect to the analysis of the 1993 data. Substantial extension of the kinematic range towards low Q2 and x has been achieved using dedicated data samples and events with initial state photon radiation. The structure function is found to increase significantly with decreasing x, even in the lowest accessible Q2 region. The data are well described by a Next to Leading Order QCD fit and the gluon density is extracted.

A measurement is presented, using data taken with the H1 detector at HERA, of the contribution of diffractive interactions to deep-inelastic electron-proton (ep) scattering in the kinematic range 8.5 < Q2 < 50GeV2, 2.4 × 10−4 < Bjorken-x < 0.0133, and 3.7 × 10−4 < χp < 0.043. The diffractive contribution to the proton structure function F2(x,Q2) is evaluated as a function of the appropriate deep-inelastic scattering variables χp, Q2, β (= χχp) using a class of deep-inelastic ep scattering events with no hadronic energy flow in an interval of pseudo-rapidity adjacent to the proton beam direction. the dependence of this contribution on χp is measured to be χp−n with n = 1.19 ± 0.06 (stat.) ± 0.07 (syst.) independent of β and Q2, which is consistent with both a diffractive interpretation and a factorisable ep diffractive cross section. A first measurement of the deep-inelastic structure of the pomeron in the form of the Q2 and β dependences of a factorised structure function is presented. For all measured β, this structure function is observed to be consistent with scale invariance.

A measurement of the proton structure function F2(x, Q2) is reported for momentum transfers squared Q2 between 4.5 GeV2 and 1600 GeV2 and for Bjorken x between 1.8 × 10−14 and 0.13 using data collected by the HERA experiment H1 in 1993. It is observed that F2 increases significantly with decreasing x, confirming our previous measurement made with one tenth of the data available in this analysis. The Q2 dependence is approximately logarithmic over the full kinematic range covered. The subsample of deep inelastic events with a large pseudo-rapidity gap in the hadronic energy flow close to the proton remnant is used to measure the “diffractive” contribution to F2.

Evidence is presented using data taken with the H1 detector at HERA for a class of deep inelastic electron-proton scattering (DIS) events (5 < Q2 < 120 GeV2) at low Bjorken-x (10−4 < x < 10−2) which have almost no hadronic energy flow in a large interval of pseudo-rapidity around the proton remnant direction and which cannot be attributed to our present understanding of DIS and fluctuations in final state hadronic fragmentation. From an integrated luminosity of 273 nb−1, 734 events, that is about 5% of the total DIS sample, have no energy deposition greater than 400 MeV forward of laboratory pseudo-rapidity ηmax = 1.8 up to the largest measurable pseudo-rapidity of about 3.65. Evidence that about 10% of observed rapidity gap events are exclusive vector meson electroproduction is presented. Good descriptions of the data are obtained using models based either on a vector meson dominance like picture, which includes a large fraction of inelastic virtual photon dissociation, or on deep inelastic electron-pomeron scattering in which the partonic sub-structure of the latter is resolved.

The cross-section for deeply virtual Compton scattering in the reaction ep→eγp has been measured with the ZEUS detector at HERA using integrated luminosities of 95.0 pb−1 of e+p and 16.7 pb−1 of e−p collisions. Differential cross-sections are presented as a function of the exchanged-photon virtuality, Q2, and the centre-of-mass energy, W, of the γ∗p system in the region 5<Q2<100 GeV2 and 40<W<140 GeV. The measured cross-sections rise steeply with increasing W. The measurements are compared to QCD-based calculations.

Machine learning is an important applied research area in particle physics, beginning with applications to high-level physics analysis in the 1990s and 2000s, followed by an explosion of applications in particle and event identification and reconstruction in the 2010s. In this document we discuss promising future research and development areas in machine learning in particle physics with a roadmap for their implementation, software and hardware resource requirements, collaborative initiatives with the data science community, academia and industry, and training the particle physics community in data science. The main objective of the document is to connect and motivate these areas of research and development with the physics drivers of the High-Luminosity Large Hadron Collider and future neutrino experiments and identify the resource needs for their implementation. Additionally we identify areas where collaboration with external communities will be of great benefit.

We use adversarial network architectures together with the Wasserstein distance to generate or refine simulated detector data. The data reflect two-dimensional projections of spatially distributed signal patterns with a broad spectrum of applications. As an example, we use an observatory to detect cosmic ray-induced air showers with a ground-based array of particle detectors. First we investigate a method of generating detector patterns with variable signal strengths while constraining the primary particle energy. We then present a technique to refine simulated time traces of detectors to match corresponding data distributions. With this method we demonstrate that training a deep network with refined data-like signal traces leads to a more precise energy reconstruction of data events compared to training with the originally simulated traces.

We present a detailed study of the large-scale anisotropies of cosmic rays with energies above 4 EeV measured using the Pierre Auger Observatory. For the energy bins [4,8] EeV and $E\geq 8$ EeV, the most significant signal is a dipolar modulation in right ascension at energies above 8 EeV, as previously reported. In this paper we further scrutinize the highest-energy bin by splitting it into three energy ranges. We find that the amplitude of the dipole increases with energy above 4 EeV. The growth can be fitted with a power law with index $\beta=0.79\pm 0.19$. The directions of the dipoles are consistent with an extragalactic origin of these anisotropies at all the energies considered. Additionally we have estimated the quadrupolar components of the anisotropy: they are not statistically significant. We discuss the results in the context of the predictions from different models for the distribution of ultrahigh-energy sources and cosmic magnetic fields.

We present the first measurement of the fluctuations in the number of muons in extensive air showers produced by ultrahigh energy cosmic rays. We find that the measured fluctuations are in good agreement with predictions from air shower simulations. This observation provides new insights into the origin of the previously reported deficit of muons in air shower simulations and constrains models of hadronic interactions at ultrahigh energies. Our measurement is compatible with the muon deficit originating from small deviations in the predictions from hadronic interaction models of particle production that accumulate as the showers develop.

A measurement is presented of elastic deeply virtual Compton scattering e++p→e++γ+p at HERA using data taken with the H1 detector. The cross section is measured as a function of the photon virtuality, Q2, and the invariant mass, W, of the γp system, in the kinematic range 2<Q2<20GeV2, 30<W<120GeV and |t|<1GeV2, where t is the squared momentum transfer to the proton. The measurement is compared to QCD based calculations.

A narrow resonance in D∗−p and D∗+p̄ invariant mass combinations is observed in inelastic electron–proton collisions at centre-of-mass energies of 300 GeV and 320 GeV at HERA. The resonance has a mass of 3099±3(stat.)±5(syst.) MeV and a measured Gaussian width of 12±3(stat.) MeV, compatible with the experimental resolution. The resonance is interpreted as an anti-charmed baryon with a minimal constituent quark composition of uuddc̄, together with the charge conjugate.

The ratio of cross sections for inelastic muon scattering on xenon and deuterium nuclei was measured at very low Bjorken x (0.000 02${\mathit{x}}_{\mathrm{Bj}}$0.25). The data were taken at Fermilab experiment E-665 with a 490 GeV/c muon beam incident on liquid deuterium and gaseous xenon targets. Two largely independent analysis techniques gave statistically consistent results. The xenon-to-deterium per-nucleon cross-section ratio is constant at approximately 0.7 for ${\mathit{x}}_{\mathrm{Bj}}$ below 0.003.

Nuclear shadowing is observed in the per-nucleon cross sections of positive muons on carbon, calcium and lead as compared to deuterium. The data were taken by Fermilab experiment E665 using inelastically scattered muons of mean incident momentum 470 GeV/c. Cross-section ratios are presented in the kinematic region 0.0001<x Bj <0.56 and 0.1<Q 2<80 GeV2. The data are consistent with no significant ν orQ 2 dependence at fixedx Bj . Asx Bj decreases, the size of the shadowing effect, as well as itsA dependence, are found to approach the corresponding measurements in photoproduction.

A search for ultra-high energy photons with energies above 1 EeV is performed using nine years of data collected by the Pierre Auger Observatory in hybrid operation mode. An unprecedented separation power between photon and hadron primaries is achieved by combining measurements of the longitudinal air-shower development with the particle content at ground measured by the fluorescence and surface detectors, respectively. Only three photon candidates at energies 1–2 EeV are found, which is compatible with the expected hadron-induced background. Upper limits on the integral flux of ultra-high energy photons of 0.027, 0.009, 0.008, 0.008 and 0.007 km−2 sr−1 yr−1 are derived at 95% C.L. for energy thresholds of 1, 2, 3, 5 and 10 EeV. These limits bound the fractions of photons in the all-particle integral flux below 0.1%, 0.15%, 0.33%, 0.85% and 2.7%. For the first time the photon fraction at EeV energies is constrained at the sub-percent level. The improved limits are below the flux of diffuse photons predicted by some astrophysical scenarios for cosmogenic photon production. The new results rule-out the early top-down models − in which ultra-high energy cosmic rays are produced by, e.g., the decay of super-massive particles − and challenge the most recent super-heavy dark matter models.

We describe a method of reconstructing air showers induced by cosmic rays using deep learning techniques. We simulate an observatory consisting of ground-based particle detectors with fixed locations on a regular grid. The detector's responses to traversing shower particles are signal amplitudes as a function of time, which provide information on transverse and longitudinal shower properties. In order to take advantage of convolutional network techniques specialized in local pattern recognition, we convert all information to the image-like grid of the detectors. In this way, multiple features, such as arrival times of the first particles and optimized characterizations of time traces, are processed by the network. The reconstruction quality of the cosmic ray arrival direction turns out to be competitive with an analytic reconstruction algorithm. The reconstructed shower direction, energy and shower depth show the expected improvement in resolution for higher cosmic ray energy.

A simulation study of the energy released by extensive air showers in the form of MHz radiation is performed using the CoREAS simulation code. We develop an efficient method to extract this radiation energy from air-shower simulations. We determine the longitudinal profile of the radiation energy release and compare it to the longitudinal profile of the energy deposit by the electromagnetic component of the air shower. We find that the radiation energy corrected for the geometric dependence of the geomagnetic emission scales quadratically with the energy in the electromagnetic component of the air shower with a second-order dependence on the atmospheric density at the position of the maximum shower development Xmax. In a measurement where Xmax is not accessible, this second order dependence can be approximated using the zenith angle of the incoming direction of the air shower with only a minor loss in accuracy. Our method results in an intrinsic uncertainty of 4% in the determination of the energy in the electromagnetic air-shower component, which is well below current experimental uncertainties.

We present a two-stage neural network architecture that enables a fully autonomous and comprehensive characterization of collision events by exclusively exploiting the four-momenta of final-state particles. We refer to the first stage of the architecture as Lorentz Boost Network (LBN). The LBN allows the creation of particle combinations representing rest frames. The LBN also enables the formation of further composite particles, which are then transformed into said rest frames by Lorentz transformation. The properties of the composite, transformed particles are compiled in the form of characteristic variables that serve as input for a subsequent network. This second network has to be configured for a specific analysis task such as the separation of signal and background events. Using the example of the classification of ttH and t+b events, we compare the separation power of the LBN approach with that of domain-unspecific deep neural networks (DNN). We observe leading performance with the LBN, even though we provide the DNNs with extensive additional input information beyond the particle four-momenta. Furthermore, we demonstrate that the LBN forms physically meaningful particle combinations and autonomously generates suitable characteristic variables.

A measurement of the derivative (d ln F_2 / d lnx)_(Q^2)= -lambda(x,Q^2) of the proton structure function F_2 is presented in the low x domain of deeply inelastic positron-proton scattering. For 5*10^(-5)<=x<=0.01 and Q^2>=1.5 GeV^2, lambda(x,Q^2) is found to be independent of x and to increase linearly with ln(Q^2).

The inclusive production of D∗±(2010) mesons in deep-inelastic scattering is studied with the H1 detector at HERA. In the kinematic region 1<Q2<100 GeV2 and 0.05<y<0.7 an e+p cross section for inclusive D∗± meson production of 8.50±0.42(stat.)+1.21−1.00(syst.) nb is measured in the visible range ptD∗>1.5 GeV and |ηD∗|<1.5. Single and double differential inclusive D∗± meson cross sections are compared to perturbative QCD calculations in two different evolution schemes. The charm contribution to the proton structure, F2c(x,Q2), is determined by extrapolating the visible charm cross section to the full phase space. This contribution is found to rise from about 10% at Q2=1.5 GeV2 to more than 25% at Q2=60 GeV2 corresponding to x values ranging from 5×10−5 to 3×10−3.

First results on inclusive $$\mathop {D^0 }\limits^{( - )} $$ andD*± production in neutral current deep inelasticep scattering are reported using data collected by the H1 experiment at HERA in 1994. Differential cross sections are presented for both channels and are found to agree well with QCD predictions based on the boson gluon fusion process. A charm production cross section for 10 GeV2≤Q2≤100 GeV2 and 0.01≤y≤0.7 of $$\sigma (ep \to ec\bar cX) = (17.4 \pm 1.6 \pm 1.7 \pm 1.4) nb$$ is derived. A first measurement of the charm contribution $$F_2^{c\bar c} (x,Q^2 )$$ to the proton structure function for Bjorkenx between 8·10−4 and 8·10−3 is presented. In this kinematic range a ratio $$F_2^{c\bar c} /F_2 = 0.237 \pm 0.021 \pm 0.041$$ is observed.

The results of a measurement of the proton structure function F2(x,Q2) and the virtual photon-proton cross section are reported for momentum transfers squared Q2 between 0.35 GeV2 and 3.5 GeV2 and for Bjorken-x values down to 6 × 10−6 using data collected by the HERA experiment H1 in 1995. The data represent an increase in kinematic reach to lower x and Q2 values of about a factor of 5 compared to previous H1 measurements. Including measurements from fixed target experiments the rise of F2 with decreasing x is found to be less steep for the lowest Q2 values measured. Phenomenological models at low Q2 are compared with the data.

We present first results on the total photoproduction cross section measurement with the H1 detector at HERA. The data were extracted from low Q2 collisions of 26.7 GeV electrons with 820 GeV protons. The γp total cross section has been measured by two independent methods in the γp center of mass energy range from 90 to 290 GeV. For an average center of mass energy of 195 GeV a value of σtot (γp) = 159 ± 7 (stat.) ± 20 (syst.) μb was obtained.

We report on the investigation of the final state in interactions of quasi-real photons with protons. The data were taken with the H1 detector at the HERA ep collider. Evidence for hard interactions is seen in both single particle spectra and jet formation. The data can best be described by inclusion of resolved photon processess as predicted by QCD.

The phase relations have been investigated experimentally at 200 and 500 MPa as a function of water activity for one of the least evolved (Indian Batt Rhyolite) and of a more evolved rhyolite composition (Cougar Point Tuff XV) from the 12·8–8·1 Ma Bruneau–Jarbidge eruptive center of the Yellowstone hotspot. Particular priority was given to accurate determination of the water content of the quenched glasses using infrared spectroscopic techniques. Comparison of the composition of natural and experimentally synthesized phases confirms that high temperatures (>900°C) and extremely low melt water contents (<1·5 wt % H2O) are required to reproduce the natural mineral assemblages. In melts containing ∼0·5–1·5 wt % H2O, the liquidus phase is clinopyroxene (excluding Fe–Ti oxides, which are strongly dependent on fO2), and the liquidus temperature of the more evolved Cougar Point Tuff sample (BJR; ∼940–1000°C) is at least 30°C lower than that of the Indian Batt Rhyolite lava sample (IBR2; 970–1030°C). For the composition BJR, the comparison of the compositions of the natural and experimental glasses indicates a pre-eruptive temperature of at least 900°C. The composition of clinopyroxene and pigeonite pairs can be reproduced only for water contents below 1·5 wt % H2O at 900°C, or lower water contents if the temperature is higher. For the composition IBR2, a minimum temperature of 920°C is necessary to reproduce the main phases at 200 and 500 MPa. At 200 MPa, the pre-eruptive water content of the melt is constrained in the range 0·7–1·3 wt % at 950°C and 0·3–1·0 wt % at 1000°C. At 500 MPa, the pre-eruptive temperatures are slightly higher (by ∼30–50°C) for the same ranges of water concentration. The experimental results are used to explore possible proxies to constrain the depth of magma storage. The crystallization sequence of tectosilicates is strongly dependent on pressure between 200 and 500 MPa. In addition, the normative Qtz–Ab–Or contents of glasses quenched from melts coexisting with quartz, sanidine and plagioclase depend on pressure and melt water content, assuming that the normative Qtz and Ab/Or content of such melts is mainly dependent on pressure and water activity, respectively. The combination of results from the phase equilibria and from the composition of glasses indicates that the depth of magma storage for the IBR2 and BJR compositions may be in the range 300–400 MPa (∼≤13 km) and 200–300 MPa (∼≤10 km), respectively.

Research Article| April 01, 2015 Melts of sediments in the mantle wedge of the Oman ophiolite Karsten M. Haase; Karsten M. Haase 1GeoZentrum Nordbayern, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schlossgarten 5, 91054 Erlangen, Germany Search for other works by this author on: GSW Google Scholar Sarah Freund; Sarah Freund 1GeoZentrum Nordbayern, Friedrich-Alexander-Universität Erlangen-Nürnberg, Schlossgarten 5, 91054 Erlangen, Germany Search for other works by this author on: GSW Google Scholar Jürgen Koepke; Jürgen Koepke 2Institute for Mineralogy, Leibniz Universität Hannover, Callinstrasse 3, 30167 Hannover, Germany Search for other works by this author on: GSW Google Scholar Folkmar Hauff; Folkmar Hauff 3GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstrasse 1-3, 24148 Kiel, Germany Search for other works by this author on: GSW Google Scholar Martin Erdmann Martin Erdmann 2Institute for Mineralogy, Leibniz Universität Hannover, Callinstrasse 3, 30167 Hannover, Germany Search for other works by this author on: GSW Google Scholar Geology (2015) 43 (4): 275–278. https://doi.org/10.1130/G36451.1 Article history received: 14 Nov 2014 rev-recd: 09 Jan 2015 accepted: 22 Jan 2015 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Karsten M. Haase, Sarah Freund, Jürgen Koepke, Folkmar Hauff, Martin Erdmann; Melts of sediments in the mantle wedge of the Oman ophiolite. Geology 2015;; 43 (4): 275–278. doi: https://doi.org/10.1130/G36451.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The rocks in the crustal section of the Oman ophiolite show an increasing input of a subduction component with time, most likely reflecting the generation of the ophiolite above a subducting slab. Field relations, new geochemical data, and Nd-Hf isotope data for felsic to mafic intrusive rocks in the mantle harzburgite from the Haylayn block in the Oman ophiolite suggest late magmatic events in a mantle wedge shortly before obduction of the ophiolite. Incompatible element contents and low εNd and εHf of the felsic rocks exclude differentiation from mafic magmas, but are consistent with an origin by partial melting of pelagic sediments similar to leucogranites in continental collision zones. These melts apparently mixed with mafic magmas resembling enriched late-stage lavas from the ophiolite. The leucogranitic intrusions into the mantle wedge confirm the transfer of melts of sediments from the subducted plate into the mantle at subduction zones. We suggest that the enrichment of Rb, K, and Pb observed in the Oman boninites is caused by addition of melts of sediments similar to those from the Haylayn block to the boninite source in the mantle wedge. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Abstract The atmospheric depth of the air shower maximum X max is an observable commonly used for the determination of the nuclear mass composition of ultra-high energy cosmic rays. Direct measurements of X max are performed using observations of the longitudinal shower development with fluorescence telescopes. At the same time, several methods have been proposed for an indirect estimation of X max from the characteristics of the shower particles registered with surface detector arrays. In this paper, we present a deep neural network (DNN) for the estimation of X max . The reconstruction relies on the signals induced by shower particles in the ground based water-Cherenkov detectors of the Pierre Auger Observatory. The network architecture features recurrent long short-term memory layers to process the temporal structure of signals and hexagonal convolutions to exploit the symmetry of the surface detector array. We evaluate the performance of the network using air showers simulated with three different hadronic interaction models. Thereafter, we account for long-term detector effects and calibrate the reconstructed X max using fluorescence measurements. Finally, we show that the event-by-event resolution in the reconstruction of the shower maximum improves with increasing shower energy and reaches less than 25 g/cm 2 at energies above 2 × 10 19 eV.

The first observation of open b production in ep collisions is reported. An event sample containing muons and jets has been selected which is enriched in semileptonic b quark decays. The visible cross section σ(ep→bb̄X→μX′)for Q2<1GeV2, 0.1<y<0.8 is measured to be 0.176±0.016(stat.)+0.026−0.017(syst.)nb for the muons to be detected in the range 35°<θμ<130° and p⊥μ>2.0GeV in the laboratory frame. The expected visible cross section based on a NLO QCD calculation is 0.104±0.017nb. The cross sections for electroproduction with Q2<1GeV2 and photoproduction are derived from the data and found to be σ(ep→ebb̄X)=7.1±0.6(stat.)+1.5−1.3(syst.)nb and σ(γp→bb̄X)=111±10(stat.)+23−20(syst.)nb at an average 〈Wγp〉∼180GeV, respectively.

With the H1 detector at the ep collider HERA, D∗ meson production cross sections have been measured in deep inelastic scattering with four-momentum transfers Q2 > 3 GeV2 and in photoproduction at energies around Wγp ≈ 88 GeV and 194 GeV. Next-to-Leading Order QCD calculations are found to describe the differential cross sections within theoretical and experimental uncertainties. Using these calculations, the NLO gluon momentum distribution in the proton, xgg(xg), has been extracted in the momentum fraction range 7.5 × 10−4 < xg < 4 × 10−2 at average scales μ2 = 25 to 50 GeV2. The gluon momentum fraction xg has been obtained from the measured kinematics of the scattered electron and the D∗ meson in the final state. The results compare well with the gluon distribution obtained from the analysis of scaling violations of the proton structure function F2.

A measurement of the inclusive cross section for the deep-inelastic scattering of positrons off protons at HERA is presented at momentum transfers 8.5 ≤ Q2 ≤ 35 GeV2 and large inelasticity <y> = 0.7, i.e. for the Bjorken-x range 0.00013 ≤ x ≤ 0.00055. Using a next-to-leading order QCD fit to the structure function F2 at lower y values, the contribution of F2 to the measured cross section at high y is calculated and, by subtraction, the longitudinal structure function FL is determined for the first time with an average value of FL = 0.52 ± 0.03 (statt)−0.22+0.25 (syst) at Q2 = 15.4 GeV2 and x = 0.000243.

Nuclear transparencies measured in exclusive incoherent ρ0 meson production from hydrogen, deuterium, carbon, calcium, and lead in muon-nucleus scattering are reported. The data were obtained with the E665 spectrometer using the Fermilab Tevatron muon beam with a mean beam energy of 470 GeV. Increases in the nuclear transparencies are observed as the virtuality of the photon increases, in qualitative agreement with the expectations of color transparency.Received 5 August 1994DOI:https://doi.org/10.1103/PhysRevLett.74.1525©1995 American Physical Society

Transverse momentum spectra of charged particles produced in deep inelastic scattering are measured as a function of the kinematic variables x_B and Q2 using the H1 detector at the ep collider HERA. The data are compared to different parton emission models, either with or without ordering of the emissions in transverse momentum. The data provide evidence for a relatively large amount of parton radiation between the current and the remnant systems.

Results on diffractive photoproduction of ψ(2S) mesons are presented using data collected between 1996 and 2000 with the H1 detector at the HERA ep collider. The data correspond to an integrated luminosity of 77 pb−1. The energy dependence of the diffractive ψ(2S) cross section is found to be similar to or possibly somewhat steeper than that for J/ψ mesons. The dependences of the elastic and proton dissociative ψ(2S) photoproduction cross sections on the squared momentum transfer t at the proton vertex are measured. The t-dependence of the elastic channel, parametrised as ebt, yields belψ(2S)=(4.31±0.57±0.46) GeV−2, compatible with that of the J/ψ. For the proton dissociative channel the result bpdψ(2S)=(0.59±0.13±0.12) GeV−2 is 2.3 standard deviations smaller than that measured for the J/ψ. With proper account of the individual wavefunctions theoretical predictions based on perturbative QCD are found to describe the measurements well.

A direct search for new particles in the H1 experiment at HERA is presented for masses ranging from 35 GeV up to ∼ 250 GeV. The data sample of 24 nb−1 accumulated during the first year of operation was analysed for signatures of scalar and vector leptoquarks, leptogluons, excited electrons and excited neutrinos with flavours of the first generation. No evidence for the production of such particles was found in various possible decay channels. Rejection limits are derived.

Air showers induced by cosmic rays create nanosecond pulses detectable at radio frequencies. These pulses have been measured successfully in the past few years at the LOw Frequency ARray (LOFAR) and are used to study the properties of cosmic rays. For a complete understanding of this phenomenon and the underlying physical processes, an absolute calibration of the detecting antenna system is needed. We present three approaches that were used to check and improve the antenna model of LOFAR and to provide an absolute calibration of the whole system for air shower measurements. Two methods are based on calibrated reference sources and one on a calibration approach using the diffuse radio emission of the Galaxy, optimized for short data-sets. An accuracy of 19% in amplitude is reached. The absolute calibration is also compared to predictions from air shower simulations. These results are used to set an absolute energy scale for air shower measurements and can be used as a basis for an absolute scale for the measurement of astronomical transients with LOFAR.

With the Auger Engineering Radio Array (AERA) of the Pierre Auger Observatory, we have observed the radio emission from 561 extensive air showers with zenith angles between 60$^\circ$ and 84$^\circ$. In contrast to air showers with more vertical incidence, these inclined air showers illuminate large ground areas of several km$^2$ with radio signals detectable in the 30 to 80\,MHz band. A comparison of the measured radio-signal amplitudes with Monte Carlo simulations of a subset of 50 events for which we reconstruct the energy using the Auger surface detector shows agreement within the uncertainties of the current analysis. As expected for forward-beamed radio emission undergoing no significant absorption or scattering in the atmosphere, the area illuminated by radio signals grows with the zenith angle of the air shower. Inclined air showers with EeV energies are thus measurable with sparse radio-antenna arrays with grid sizes of a km or more. This is particularly attractive as radio detection provides direct access to the energy in the electromagnetic cascade of an air shower, which in case of inclined air showers is not accessible by arrays of particle detectors on the ground.

Journal of Industrial EcologyVolume 25, Issue 4 p. 1034-1050 RESEARCH AND ANALYSIS Open Access Environmental impacts of the future supply of rare earths for magnet applications Sabine Langkau, Corresponding Author sabine.langkau@isi.fraunhofer.de orcid.org/0000-0003-3443-2920 Competence Center Sustainability and Infrastructure Systems, Fraunhofer Institute for Systems and Innovation Research ISI, Karlsruhe, Germany Correspondence Sabine Langkau, Competence Center Sustainability and Infrastructure Systems, Fraunhofer Institute for Systems and Innovation Research ISI, Breslauer Straße 48, 76139 Karlsruhe, Germany. Email: sabine.langkau@isi.fraunhofer.deSearch for more papers by this authorMartin Erdmann, Federal Institute for Geosciences and Natural Resources, BGR, Hannover, GermanySearch for more papers by this author Sabine Langkau, Corresponding Author sabine.langkau@isi.fraunhofer.de orcid.org/0000-0003-3443-2920 Competence Center Sustainability and Infrastructure Systems, Fraunhofer Institute for Systems and Innovation Research ISI, Karlsruhe, Germany Correspondence Sabine Langkau, Competence Center Sustainability and Infrastructure Systems, Fraunhofer Institute for Systems and Innovation Research ISI, Breslauer Straße 48, 76139 Karlsruhe, Germany. Email: sabine.langkau@isi.fraunhofer.deSearch for more papers by this authorMartin Erdmann, Federal Institute for Geosciences and Natural Resources, BGR, Hannover, GermanySearch for more papers by this author First published: 27 November 2020 https://doi.org/10.1111/jiec.13090Citations: 5 Funding informationResearch leading to this publication was funded within the r4-programm of the German Ministry of Education and Research (BMBF, project reference number 033R124C) and within the Fraunhofer Lighthouse Project Criticality of Rare Earths. Editor Managing Review: Richard Wood AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat Abstract The environmental impacts of rare earth mining have recently caused public concern, because demand for the rare earth elements neodymium (Nd), praseodymium (pr), dysprosium (Dy), and terbium (Tb) is expected to increase strongly as a result of their use in magnets for electric cars and other emerging applications. Therefore, we analyzed the future environmental impacts of producing these rare earth metals per kilogram and for global production in the year 2035 to obtain insights into their relevance and draw conclusions about suitable mitigation measures. We introduced a new stepwise approach that combines future scenarios of metal demand, policy measures, mining sites, and environmental conditions with life cycle assessment data sets. The environmental impacts of 1kg of Nd, Pr, Dy, and Tb will probably decrease by 2035. In contrast, the environmental impacts of the global production of these metals for magnet applications might increase or decrease depending on the development of demand and the environmental conditions of mining and production. Regarding mitigation measures, the attempts included in the Chinese consolidation strategy (improvement of the environmental conditions of mining, prevention of illegal mining) are the most promising to reduce impacts in the categories human toxicity, freshwater ecotoxicity and, in the case of Nd/Pr, also in eutrophication and acidification. For the remaining categories, reducing the increase in demand (e.g., by improving material efficiency) is the most promising measure. Enhancing the environmental performance of foreground processes has larger potential benefits than improving background processes for most impact categories, including human toxicity as the most relevant impact category following normalization. This article met the requirements for a gold-gold JIE data openness badge described at http://jie.click/badges. 1 INTRODUCTION Electric vehicles are politically supported as green technologies to reduce CO2 emissions and thereby mitigate the challenge of climate change. However, their successful market diffusion will strongly increase the demand for specialty metals, for example, lithium and cobalt for batteries as well as for rare earths (RE) for the magnets used in electric motors (Marscheider-Weidemann et al., 2016). This raises economic concerns about supply shortages and price fluctuations (Ad-Hoc Working Group on Defining Critical Raw Materials, 2010; Glöser-Chahoud, 2017; Schrijvers et al., 2020; Tercero Espinoza et al., 2020). In addition, much public attention has been drawn to environmental and social problems identified in the supply chains of the respective specialty metals (Amnesty International 2016; Bodenheimer, 2014; Bontron, 2012; Walz, Bodenheimer, & Gandenberger, 2016). While the environmental burden of these specialty metals is not specifically due to their usage in green future technologies, a significant increase in the environmental impacts of the worldwide production of these specialty metals is to be expected from the unusually strong market diffusion of future technologies (Langkau & Tercero Espinoza, 2018; Marscheider-Weidemann et al., 2016). Therefore, there is a need to analyze what the most effective measures could be to mitigate any future increase in environmental impacts. Methods of future research (Gerhold et al. 2015), especially the scenario technique, can help to answer this question by describing and modeling different possible future developments, assessing which are desirable, identifying the key parameters to influence future developments and, deriving policy recommendations. Scenarios on future demand for the RE neodymium (Nd), dysprosium (Dy), praseodymium (Pr), and terbium (Tb) can be found in the literature up to the year 2035 (Marscheider-Weidemann et al., 2016). In contrast, data concerning the environmental impacts of their production is only available for the present or recent past (Lee & Wen, 2017; Marx, Schreiber, Zapp, & Walachowicz, 2018; Schreiber et al., 2016; Zapp, Marx, Schreiber, Friedrich, & Voßenkaul, 2018). Hence, this study aims at constructing scenarios of the future environmental impacts of Nd, Dy, Pr, and Tb per kg and for worldwide production. Based on these scenarios, we derive recommendations for mitigation measures. To analyze the environmental impacts of future metal production, van der Voet, van Oers, Verboon, and Kuipers (2019) and Kuipers, van Oers, Verboon, and van der Voet (2018) developed a new approach that combines life cycle assessment (LCA) with future scenarios of metal demand. They classified this method as part of the life cycle sustainability assessment (LCSA) framework. This framework is intended to broaden the life cycle approach from the environmental assessment of products or services to more universal questions of sustainability science and thereby derive recommendations for society and policy makers (Guinée & Heijungs, 2011). Van der Voet et al. (2019) describe their method for assessing the future environmental impacts of metal production in three successive steps: (1) LCA to determine the environmental impacts of producing 1 kg of refined metal, (2) analysis of future changes in these environmental impacts, and (3) multiplying the future environmental impacts of 1 kg metal by the future production worldwide. In contrast to the mass metals examined in Kuipers et al. (2018) and van der Voet et al. (2019), our study focuses on specialty metals. The overall production quantity of specialty metals is smaller than mass metals by several orders of magnitude, but the complex processes involved in their mining and refining mean the environmental impacts of their global production are still relevant (Nuss & Eckelman, 2014). The global production of these specialty metals is often provided by only a few countries or even mining sites (DERA, n.d.). Therefore, any changes in demand have strong influence on changes in mining sites, which in turn influence the environmental impacts of mining. Consequently, demand changes are relevant for the development of LCA data over time. As a result, it is not possible for us to follow the three steps of (van der Voet et al., 2019), which assume demand development to be irrelevant to the development of the environmental impacts per kilogram of metal. We therefore propose a novel stepwise approach to analyzing the future environmental impacts of specialty metal production per kilogram as well as of global production by combining LCA data on different mining sites with expert knowledge on the potential contribution of these mining sites to global metal supply. 2 METHODS, ASSUMPTIONS, AND SCENARIOS Our method can be described as an iterative approach comprising four steps. First, we analyze which parameters influence the future development of the environmental impacts of 1 kg of metal and how these parameters interrelate. Second, we derive assumptions and sub-scenarios for the most influential parameters. Third, we combine these assumptions and sub-scenarios into consistent overall scenarios. Fourth, we calculate the environmental impacts per kilogram and for global production to derive recommendations. We describe these four steps in more detail in the following sections. The baseline year of this study is 2013. Scenarios refer to the horizon year 2035. 2.1 Identification of influential factors Causal loop diagrams (CLD) visualize the interdependencies of parameters in a dynamic system at one point in time. They can be used as a starting point for the dynamic modeling of complex systems, but also more generally to document interdependencies in a complex system or to make mental models transparent (de Vries, 2012). Figure 1 depicts the parameters influencing the future environmental impacts of RE production, and their mutual dependencies. In the following, we summarize the existing knowledge on these parameters, and derive assumptions and sub-scenarios for them. FIGURE 1Open in figure viewerPowerPoint Causal loop diagram (CLD) displaying the different parameters relevant for the future change in environmental impacts of production of Nd, Pr, Dy, Tb as well as their various interdependencies 2.2 Sub-scenarios of influential parameters 2.2.1 Metal demand and supply Due to their high performance, NdFeB magnets are used in future technologies such as traction motors in electric cars and generators in wind power plants (Marscheider-Weidemann et al., 2016; Roskill Information Services, 2011). The magnets generally contain the rare earth element Nd (about 33 mass percent), while Dy may substitute small quantities of Nd (<10%) to improve their properties (Glöser-Chahoud, 2017; Hoenderdaal, Tercero Espinoza, Marscheider-Weidemann, & Graus, 2013). Furthermore, Nd can be replaced by Pr up to a ratio of 3:1 without negative impacts on performance (Buchert, Manhart, Bleher, & Pingel, 2012). The typically used ratio is 5:1 (Glöser-Chahoud, 2017). Likewise, substitution of Dy by Tb is possible (Schüler, Buchert, Liu, Dittrich, & Merz, 2011). Therefore, we considered the four elements Nd, Pr, Dy, and Tb in our demand analysis. Nd and Pr belong to the more abundant light rare earth elements (LRE), while Dy and Tb are assigned to the less abundant heavy rare earth elements (HRE) (Elsner, 2011). Based on typically applied substitution ratios and the average composition of RE ores (BGR, 2019), we assume that the LRE demand for magnets will be met by 23% Pr and 77% Nd, while HRE demand will be covered by 14% Tb and 86% Dy. In 2013, the total demand for NdFeB applications was 28,900 t of Nd/Pr and 2,000 t of Dy/Tb (Marscheider-Weidemann et al., 2016). For comparison, data on the global production of Nd/Pr and Dy/Tb can be found in Supporting Information S1 for the years 2013 and 2018 (BGR, 2019). To estimate the future demand for Nd/Pr and Dy/Tb for NdFeB magnets, we used scenarios published in Marscheider-Weidemann et al. (2016). The scenarios include detailed analyses of the demand for electric cars, wind power plants, and electric bikes as well as general assumptions for other magnet applications. Moreover, they consider technological alternatives competing with the NdFeB magnet technology, which are especially widespread for wind power plants. Different assumptions concerning market diffusion of applications, market share of the NdFeB magnet technology, and success of material efficiency measures resulted in 27 scenarios. For this study, we chose three of those scenarios to reflect high, medium, and low demand increases. The respective values for the annual global demand in 2035 are: low demand (A1): Nd/Pr: 42,100 t, Dy/Tb: 3,200 t medium demand (A2): Nd/Pr: 62,400 t, Dy/Tb: 7,200 t high demand (A3): Nd/Pr: 81,700 t, Dy/Tb: 13,700 t Nd, Pr, Dy, and Tb are more expensive than other RE (e.g., lanthanum (La) and cerium (Ce)) since they are a main target of the mining of RE, which usually occur together in mining sites (Elsner, 2011). Consequently, other RE are often mined in excess and can be considered a by-product. Furthermore, the strongest demand increase in the future is expected for magnet applications (due to the growing demand for electric cars, wind power, and others) (Marscheider-Weidemann et al., 2016; Roskill Information Services, 2011). Consequently, we make the following assumptions: Assumptions A: Mining and production of various RE is determined mainly by the demand for Nd, Pr, Dy, and Tb for magnet applications in the future. The total amount of Nd, Pr, Dy, Tb mined and produced in 2035 is equal to the demand for these metals in 2035. Total supply of Nd/Pr and Dy/Tb in 2035 is therefore assumed to be equal to the demand values given above. For simplification, these assumptions neglect misfits between demand and production, for example, due to stock piling, surplus capacities, or supply shortages. 2.2.2 Framing conditions for mining and production China has been dominating the global RE market since the late 1990s. China's contribution to global mining production exceeded 90% in 2013 (BGR, 2019). According to the official figures, mining production outside China had increased to 22% by 2018, but illegal production in China had a high share of more than 50% in global production (Schüler-Zhou, 2018). In the case of HRE like Dy and Tb, temporary mining in Myanmar does not curtail the quasi monopoly of China because the ores are processed at Chinese plants, leaving production under Chinese control (BGR, 2019). More details on the global mining production between 2010 and 2018 can be found in Supporting Information S1. According to systemic and game-theoretical analyses, China will probably sustain its dominant position in RE supply. Among others, Han, Ge, and Lei (2015) conclude that Chinese export restrictions alone will decide to what extent future mining will take place outside China. Additionally, Machacek and Fold (2014) argue that Chinese companies will always dominate the global production of RE, though mining will not necessarily take place mainly inside China, but rather Chinese companies will control mining sites abroad. Furthermore, Klossek, Kullik, and van den Boogaart (2016) conclude that none of the strategies proposed so far will enable the United States, European Union, or Japan to prevent the shift of higher value parts of the RE value chain to China. Therefore, we make the following basic assumption: Assumption B: China will sustain its dominance of RE supply in the future. Mining and processing will remain mainly under the control of Chinese companies, even if they take place in other countries. At the same time, higher value parts of the value chain will be established within China. Consequently, mining sites as well as the environmental conditions of RE production are mainly dependent on decisions made in China, that is, agreements made and enforced within the Chinese consolidation strategy. In 2011, the Chinese government implemented numerous official regulatory measures for a consolidation of the RE market. These measures address surplus production and price decay as well as environmental concerns. They include closing illegal mines, raising environmental standards, increasing mining fees, and R&D for environmentally friendlier mining and recycling. It was particularly difficult for small enterprises to meet the new environmental standards. Hence, the consolidation strategy so far has led to the so-called 1 + 5 structure (China Northern Rare Earth Group + five companies from Southern China). These six large companies control 22 of 23 (official) mines and 54 of 59 processing facilities (Schüler-Zhou, 2018). The potential future success of the consolidation strategy is a subject of controversial discussion (e.g., Han et al., 2015; Wübbeke, 2013). We summarized the influencing parameters in Supporting Information S1. Based on those considerations, we constructed three basic scenarios B1–B3 to cover possible developments. Within the three basic scenarios B1–B3 we assumed the success of the Chinese consolidation strategy to be great (B1), moderate (B2), or little (B3), respectively. Associated sub-scenarios of the contribution of mining sites outside China and environmental conditions will be outlined in the following sections. 2.2.3 Share of different mining sites and illegal production Data on the shares of different mining sites in the global supply of Nd/Pr and Dy/Tb can be found in Supporting Information S1 for the years 2013 and 2018. For the future shares of different mining sites, an important parameter within the Chinese consolidation strategy is the mining and processing quota, which is the official limit to the total amount that can be produced within China. This quota is supposed to avoid surplus production and the related price decay and environmental burden. However, despite an official production quota of 105,000 metric tons per annum (tpa) REO from 2014–2017, processing capacities of 300,000 tpa were still in place in 2016 (Schüler-Zhou, 2018). Companies filled the surplus capacities by processing illegally mined RE ores in order to increase their profitability, thus undermining the official quota. The target processing capacity of 200,000 tpa is to be reached by 2020 according to the Chinese development plan for the RE industry (MIIT, 2016). Since global demand and Chinese demand are expected to grow, mining and processing quotas are likely to increase as well. Hence, for the official mining and processing quota in 2035, we assumed 200,000 metric tpa in the scenario of great consolidation success, 250,000 tpa in the scenario of moderate consolidation success, and 300,000 tpa in the scenario of little consolidation success. The share of illegal or unofficial mining did not change significantly between 2013 and 2018 (BGR, 2019; for details see Supporting Information S2). For Dy and Tb from ionic clay deposits in Southern China, the illegal mining share was still about 60% in 2018; for Nd and Pr from carbonatite deposits the unofficial contribution was about 15% (BGR, 2019). The future share of illegal mining depends strongly on the success of the consolidation strategy. We assumed that illegal mining is entirely eliminated only in the scenario of great consolidation success, while it remains at 26% and 42% for Dy/Tb from ionic clays in scenarios of moderate and little success, respectively. All further assumptions can be found in Supporting Information S2. Mining sites outside China are assumed to cover demand, which is not covered by legal or illegal mining within China. These might be mining sites already in production today (e.g., Mount Weld, Australia), or newly developed sites (e.g., Norra Kärr, Sweden). For each of the nine possible combinations of the scenarios of demand (A1–A3) and consolidation success (B1–B3), mining sites most likely to contribute to global production were combined into sub-scenarios of supply according to the following characteristics: Development stage of new mining projects (operating and potential increase in production > preproduction > feasibility > prefeasibility/scoping) Approved mining and processing techniques, existing infrastructure (or expenditure for its construction) Best fit of deposit composition to demand, RE content in general (especially ratio of heavy RE like Dy, Tb to light RE like Nd, Pr) Amount of potential annual production/measured resources Th and U contamination, environmental burden in general Figure 2 shows the currently producing sites as well as the most promising projects outside of China selected using these five criteria. They are grouped into deposit types (DT) according to similarities in their potential contribution. Assumptions about potential annual production rates and composition of the deposits are based on data from (pre)feasibility studies, annual reports, commercial databases, and further literature (S&P Global 2019; Weng, Haque, Mudd, & Jowitt, 2016; Zhou, Zhongxue, & Congcong, 2017). In the following, we briefly describe the properties of deposit types 1–6 with special regards to selection criteria 1–5. FIGURE 2Open in figure viewerPowerPoint Close up of mines currently producing REO and potential new mining sites outside China (BGR, 2019). For a detailed description of the possible contribution from different deposit types (DT 1–6) see text Deposit type 1: Increasing the production of currently producing mines is the easiest option to implement. Mt. Weld (AUS; from 18,500 t in 2018 to a maximum of 45,000 tpa) and Mt. Pass (USA; from 11,000 t in 2018 to a maximum of 20,000 tpa) could quickly double their production according to company information. However, these deposits provide only small amounts of HRE. Deposit type 2: Peralkaline deposits bear numerous complex rare earth minerals, so processing the ores is very difficult, which is why these deposits are currently not industrially exploited. However, peralkaline deposits have significant advantages over other deposits: With comparatively large amounts of HRE, their composition is ideal for the ratio of HRE/LRE demanded for magnets. Moreover, they contain only small amounts of thorium and uranium and their processing has a comparatively low environmental impact (Weng et al., 2016). Thus, various research efforts are dedicated to developing an effective processing route for ores from peralkaline deposits. While DT 2 summarizes deposits with eudialyte as the main RE mineral (Schreiber et al., 2016). Deposit type 3: It includes further peralkaline deposits, mainly with the RE mineral allanite. We have separated these deposit types, because an initial breakthrough in establishing a processing route for one of the above-mentioned RE minerals would lead to exploitation of deposits with that RE mineral. Deposit type 4: Besides the large carbonatite deposits that are currently in production (e.g., Bayan Obo, CHN, Mt. Weld, AUS, Mt. Pass, USA), several other deposits are known. Processing techniques for their main RE minerals monazite and bastnaesite are well established. Thus, it would be comparatively easy to start production. However, especially monazite ore may be rich in thorium that could raise environmental concerns. Moreover, this deposit type provides only minor amounts of HRE. Therefore, a strong production increase in these deposits would exacerbatethe supply imbalance of the mainly required RE (Nd/Pr and Dy/Tb). Deposit type 5: A limited number of other advanced explored deposits with different characteristics is known (cf., Supporting Information S1).They are selected according to the method described above. Deposit type 6: Ionic clay deposits supply a major amount of the presently available HRE. Exploitation takes place mainly in China with a high share of illegal mining, enabled by the low technical requirements for producing high-grade RE concentrates from these deposits. Outside China, ionic clay RE deposits are rare and at a relatively low development stage. Nevertheless, we found these deposits are needed to meet high HRE demand in the respective future scenarios (A3). Detailed information on all the deposits considered is listed in Supplementary Information S1. Tables 1 and 2 summarize the supply scenarios with production shares of mining sites outside China (DT 1–6) for the different combinations of sub-scenarios of demand (A1–A3) and success of consolidation (B1–B3). In order to supply the expected market for Nd/Pr and Dy/Tb, and to avoid an imbalance, the mining supply of the different rare earth elements has to be considered (selection criteria 3). Thus, exploitation of peralkaline deposits with relatively high HRE content is more likely than an unlimited production increase in mines currently producing carbonatite deposits with low HRE contents. The balance problem that results with high demand (A3) combined with limited success of Chinese consolidation (B3) leads to significant changes in the share of different mining sites. Mines currently producing such as Mt. Weld (AUS) and Mt. Pass (USA) then become potentially uneconomic due to decreasing prices of LRE and are not considered in the scenario A3B3. TABLE 1. Share in potential production of Nd and Pr outside China depending on different scenarios of future demand (A1–A3) and the success of the Chinese consolidation process (B1–B3). The location of the mines in the different scenarios is shown in Figure 2. Details for the deposit types (DT1–6) are given in the text and in Supporting Information S1 NdO + PrO B1 great consolidation success B2 moderate consolidation success B3 little consolidation success A1 low demand 14.8% production outside China Reduced production compared to current state (2018), no additional deposits necessary 9.9% Mt. Weld (AUS) 3.9% Mt. Pass (USA) 1.0% others Surplus production of 1,700 tpa 11.8% production outside China Reduced production compared to current state (2018), no additional deposits necessary 7.9% Mt. Weld (AUS) 3.1% Mt. Pass (USA) 0.8% others Surplus production of 13,000 tpa 9.8% production outside China Reduced production compared to current state (2018), no additional deposits necessary 6.5% Mt. Weld (AUS) 2.6% Mt. Pass (USA) 0.7% others Surplus production of 24,400 tpa A2 medium demand 40.7% production outside China 21.6% current + increasing production of Mt. Weld (AUS) and Mt. Pass (USA)—DT 1 18.1% peralkaline deposits—DT 2 + 3 0.2% other advanced projects—DT 5 0.7% other currently producing deposits 23.6% production outside China 21.4% current + increasing production of Mt. Weld (AUS) and Mt. Pass (USA)—DT 1 1.5% peralkaline deposits—DT 2 0.7% other currently producing deposits 9.8% production outside China Reduced production compared to current state (2018), no additional deposits necessary 6.5% Mt. Weld 2.6% Mt. Pass 0.7% others Surplus production of 4,000 tpa A3 high demand 54.9% production outside China 16.6% current + increasing production of Mt. Weld (AUS) and Mt. Pass (USA)—DT 1 17.7% peralkaline deposits—DT 2 + 3 10.6% further carbonatite deposits—DT 4 7.9% other advanced projects—DT 5 2.1% ionic clay—DT 6 41.6% production outside China 14.8% current + increasing production of Mt. Weld (AUS) and Mt. Pass (USA)—DT 1 16.2% peralkaline deposits—DT 2 + 3 8.0% further carbonatite deposits—DT 4 0.5% other advanced projects—DT 5 2.1% ionic clay—DT 6 27.0% production outside China No production at currently active mines outside of China due to balance problems (see text) 16.4% peralkaline deposits —DT 2 + 3 8.1% further carbonatite deposits—DT 4 0.4% other advanced projects—DT 5 2.1% ionic clay—DT 6 TABLE 2. Share in potential production of Dy and Tb outside China depending on different scenarios of future demand (A1–A3) and success of the Chinese consolidation process (B1–B3). Details for the deposit types (DT 1–6) are given in the text and in Supporting Information S1 DyO + TbO B1 great consolidation success B2 moderate consolidation success B3 little consolidation success A1 low demand 0% production outside China No additional deposits necessary Surplus production of 2,000 tpa 0% production outside China No additional deposits necessary Surplus production of 3,700 tpa 0% production outside China No additional deposits necessary Surplus production of 5,500 tpa A2 medium demand 30.8% production outside China 2.3% current + increasing production of Mt. Weld (AUS) and Mt. Pass (USA)—DT 1 24.0% peralkaline deposits—DT 2 + 3 4.5% other advanced projects—DT 5 7.1% production outside China 2.2% current + increasing production of Mt. Weld (AUS) and Mt. Pass (USA)—DT 1 4.9% peralkaline deposits—DT 0% production outside China No additional deposits necessary Surplus production of 1,300 tpa A3 high demand 41.2% production outside China 2.0% current + increasing production of Mt. Weld (AUS) and Mt. Pass (USA)—DT 1 24.0% peralkaline deposits—DT 2 + 3 4.6% further carbonatite deposits—D

Abstract We introduce a Python package that provides simple and unified access to a collection of datasets from fundamental physics research—including particle physics, astroparticle physics, and hadron- and nuclear physics—for supervised machine learning studies. The datasets contain hadronic top quarks, cosmic-ray-induced air showers, phase transitions in hadronic matter, and generator-level histories. While public datasets from multiple fundamental physics disciplines already exist, the common interface and provided reference models simplify future work on cross-disciplinary machine learning and transfer learning in fundamental physics. We discuss the design and structure and line out how additional datasets can be submitted for inclusion. As showcase application, we present a simple yet flexible graph-based neural network architecture that can easily be applied to a wide range of supervised learning tasks. We show that our approach reaches performance close to dedicated methods on all datasets. To simplify adaptation for various problems, we provide easy-to-follow instructions on how graph-based representations of data structures, relevant for fundamental physics, can be constructed and provide code implementations for several of them. Implementations are also provided for our proposed method and all reference algorithms.

Abstract The inference of physical parameters from measured distributions constitutes a core task in physics data analyses. Among recent deep learning methods, so-called conditional invertible neural networks provide an elegant approach owing to their probability-preserving bijective mapping properties. They enable training the parameter-observation correspondence in one mapping direction and evaluating the parameter posterior distributions in the reverse direction. Here, we study the inference of cosmic-ray source properties from cosmic-ray observations on Earth using extensive astrophysical simulations. We compare the performance of conditional invertible neural networks (cINNs) with the frequently used Markov Chain Monte Carlo (MCMC) method. While cINNs are trained to directly predict the parameters’ posterior distributions, the MCMC method extracts the posterior distributions through a likelihood function that matches simulations with observations. Overall, we find good agreement between the physics parameters derived by the two different methods. As a result of its computational efficiency, the cINN method allows for a swift assessment of inference quality.

The elastic electroproduction of φ mesons is studied at HERA with the H1 detector for photon virtualities 1<Q2<15GeV2 and hadronic centre of mass energies 40<W<130 GeV. The Q2 and t dependences of the cross section are extracted (t being the square of the four-momentum transfer to the target proton). When plotted as function of (Q2 + MV2) and scaled by the appropriate SU(5) quark charge factor, the φ meson cross section agrees within errors with the cross sections of the vector mesons V = ρ, ω and J/ψ. A detailed analysis is performed of the φ meson polarisation state and the ratio of the production cross sections for longitudinally and transversely polarised φ mesons is determined. A small but significant violation of s-channel helicity conservation (SCHC) is observed.

The production of transverse energy in deep inelastic scattering is measured as a function of the kinematic variables $x$ and $Q^2$ using the H1 detector at the ep collider HERA. The results are compared to the different predictions based upon two alternative QCD evolution equations, namely the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) and the Balitsky-Fadin-Kuraev-Lipatov (BFKL) equations. In a pseudorapidity interval which is central in the hadronic centre of mass system between the current and the proton remnant fragmentation region the produced transverse energy increases with decreasing $x$ for constant $Q^2$. Such a behaviour can be explained with a QCD calculation based upon the BFKL ansatz. The rate of forward jets, proposed as a signature for BFKL dynamics, has been measured.

The cross section for the elastic photoproduction of ϱ0 mesons (γp → ϱ0p) has been measured with the H1 detector at HERA for two average photon-proton centre-of-mass energies of 55 and 187 GeV. The lower energy point was measured by observing directly the ϱ0 decay giving a cross section of 9.1 ± 0.9 (stat.) ± 2.5 (syst.) μb. The logarithmic slope parameter of the differential cross section, dσ/dt, is found to be 10.9 ± 2.4 (stat.) ± 1.1 (syst.) GeV−2. The ϱ0 decay polar angular distribution is found to be consistent with s-channel helicity conservation. The higher energy cross section was determined from analysis of the lower part of the hadronic invariant mass spectrum of diffractive photoproduction and found to be 13.6 ± 0.8 (stat.) ± 2.4 (syst.) μb.

Inclusive production cross sections are measured in deep inelastic scattering at HERA for meson states composed of a charm quark and a light antiquark or the charge conjugate.The measurements cover the kinematic region of photon virtuality 2 < Q 2 < 100 GeV 2 , inelasticity 0.05 < y < 0.7, D meson transverse momenta p t (D) ≥ 2.5 GeV and pseudorapidity |η(D)| ≤ 1.5.The identification of the D-meson decays and the reduction of the combinatorial background profit from the reconstruction of displaced secondary vertices by means of the H1 silicon vertex detector.The production of charmed mesons containing the light quarks u, d and s is found to be compatible with a description in which the hard scattering is followed by a factorisable and universal hadronisation process.

Replenished axial melt lenses at fast-spreading mid-oceanic ridges may move upward and intrude into the overlying hydrothermally altered sheeted dikes, resulting in high-grade contact metamorphism with the potential to trigger anatexis in the roof rocks. Assumed products of this process are anatectic melts of felsic composition and granoblastic, two-pyroxene hornfels, representing the residue after partial melting. Integrated Ocean Drilling Program Expeditions 309, 312, and 335 at Site 1256 (eastern equatorial Pacific) sampled such a fossilized oceanic magma chamber. In this study, we simulated magma chamber roof rock anatectic processes by performing partial melting experiments using six different protoliths from the Site 1256 sheeted dike complex, spanning a lithological range from poorly to strongly altered basalts to partially or fully recrystallized granoblastic hornfels. Results show that extensively altered starting material lacking primary magmatic minerals cannot reproduce the chemistry of natural felsic rocks recovered in ridge environments, especially elements sensitive to hydrothermal alteration (e.g., K, Cl). Natural geochemical trends are reproduced through partial melting of moderately altered basalts from the lower sheeted dikes. Two-pyroxene hornfels, the assumed residue, were reproduced only at low melting degrees (<20 vol%). The overall amphibole absence in the experiments confirms the natural observation that amphibole is not produced during peak metamorphism. Comparing experimental products with the natural equivalents reveals that water activity (aH2O) was significantly reduced during anatectic processes, mainly based on lower melt aluminum oxide and lower plagioclase anorthite content at lower aH2O. High silica melt at the expected temperature (1000–1050 °C; peak thermal overprint of two-pyroxene hornfels) could only be reproduced in the experimental series performed at aH2O = 0.1.

Abstract The Pierre Auger Observatory, at present the largest cosmic-ray observatory ever built, is instrumented with a ground array of 1600 water-Cherenkov detectors, known as the Surface Detector (SD). The SD samples the secondary particle content (mostly photons, electrons, positrons and muons) of extensive air showers initiated by cosmic rays with energies ranging from 10 17 eV up to more than 10 20 eV. Measuring the independent contribution of the muon component to the total registered signal is crucial to enhance the capability of the Observatory to estimate the mass of the cosmic rays on an event-by-event basis. However, with the current design of the SD, it is difficult to straightforwardly separate the contributions of muons to the SD time traces from those of photons, electrons and positrons. In this paper, we present a method aimed at extracting the muon component of the time traces registered with each individual detector of the SD using Recurrent Neural Networks. We derive the performances of the method by training the neural network on simulations, in which the muon and the electromagnetic components of the traces are known. We conclude this work showing the performance of this method on experimental data of the Pierre Auger Observatory. We find that our predictions agree with the parameterizations obtained by the AGASA collaboration to describe the lateral distributions of the electromagnetic and muonic components of extensive air showers.

The diffractive production of ρ0(770 @#@) mesons in muon-proton interactions is studied in the kinematic region 0.15 GeV2 < Q2 < 20 GeV2 and 20 GeV < ? < 420 GeV. The data were obtained in the Fermilab fixed-target experiment E665 with primary muons of 470 GeV energy. Results are presented on the Q2, x and ? dependence of the cross section, on the shape of the ρ+ρt - mass spectrum, on the slope of the diffraction peak and on the production and decay angular distributions of the ρ0(770). The cross section for diffractive production of ρ0 by virtual photons on protons depends mainly on Q2. At fixed Q2, no significant dependence on x or ? is observed. The extrapolation to Q2 = 0 yields a photoproduction cross section of (10.30 ± 0.33) μb. The slope of the t′ distribution has a value of (7.0 ± 0.2) GeV−2, with a tendency to decrease as Q2 increases. The production and decay angular distributions of the ρ0 depend strongly on Q2 and are consistent with s-channel helicity conservation. The ratio R = σ l /σ t deduced from the decay angular distributions rises strongly with Q2, passing the value of 1 at Q2 ≈ 2 GeV2.

The total cross sections for the elastic electroproduction of P and Jψ mesons for Q2 > 8 GeV2 and 〈W〉 ⋍ 90 GeV/c2 are measured at HERA with the H1 detector. The measurements are for an integrated electron-proton luminosity of ⋍3 pb−1. The dependences of the total virtual photon-proton (γ∗p) cross sections on Q2, W and the momentum transfer squared to the proton (t), and, for the ϱ, the dependence on the polar decay angle (cos θ∗ are presented. The Jψ : ∂ cross section ratio is determined. The results are discussed in the light of theoretical models and of the interplay of hard and soft physics processes.

At the electron-proton collider HERA the inclusive D∗± meson photoproduction cross section has been measured with the H1 detector in two different, but partly overlapping, kinematical regions. For the first, where 〈Wγp〉 ≈ 200 GeV and Q2 < 0.01 GeV2, the result is σ(γp → ccX) = (13.2 ± 2.2−1.7 −4.8+2.1 +9.9) μb. The second measurement for Q2 < 4 GeV2 yields σ(γp → ccX) = (9.3 ± 2.1−1.8 −3.2+1.9 +6.9) μb at 〈Wγp〉 ≈ 142 GeV and σ(γp → ccX) = (20.6 ± 5.5−3.9 −7.2+4.3 +15.4 μb at 〈Wγp〉 ≈ 230 GeV, respectively. The third error accounts for an additional uncertainty due to the proton and photon parton density parametrizations. Differential cross sections are presented as a function of the D∗± transverse momentum and rapidity. The results compare reasonably well with next-to-leading order QCD calculations. Evidence for diffractive photoproduction of charm quarks is presented.

Results on forward charged hadrons in 490 GeV deep-inelastic muon scattering are presented. The transverse momenta, azimuthal asymmetry, and energy flow of events with four or more forward charged hadrons are studied. The range of the invariant hadronic mass squared 300<W2<900 GeV2/c4 extends higher than previous deep-inelastic muon scattering experiments. Data are compared to the predictions of the Lund Monte Carlo model with perturbative QCD simulated by matrix elements, parton showers, and color dipole radiation. All of the QCD-based models are consistent with the data while a model without QCD processes is not. Correlations with the multiplicity-independent event variable Π≃Σ|pT| are studied. The relationship between the azimuthal asymmetry and transverse momentum of forward hadrons is also presented. The data are most consistent with intrinsic parton transverse momentum squared k2T of 0.25 GeV2/c2.Received 14 June 1993DOI:https://doi.org/10.1103/PhysRevD.48.5057©1993 American Physical Society

We present a QCD analysis of the proton structure function F2 measured by the H1 experiment at HERA, combined with data from previous fixed target experiments. The gluon density is extracted from the scaling violations of F2 in the range 2 · 10−4 < x < 3 · 10−2 and compared with an approximate solution of the QCD evolution equations. The gluon density is found to rise steeply with decreasing x.

The diffractive photoproduction of J/psi mesons is measured with the H1 detector at the ep collider HERA using an integrated luminosity of 78 pb^-1. The differential cross section d sigma(gamma p -> J/psi Y) / d t is studied in the range 2 < |t| < 30 GeV^2, where t is the square of the four-momentum transferred at the proton vertex. The cross section is also presented as a function of the photon-proton centre-of-mass energy W in three t intervals, spanning the range 50 < W < 200 GeV. A fast rise of the cross section with W is observed for each t range and the slope for the effective linear Pomeron trajectory is measured to be alpha^\prime= -0.0135 \pm 0.0074 (stat.) \pm 0.0051 (syst.) GeV^-2. The measurements are compared with perturbative QCD models based on BFKL and DGLAP evolution. The data are found to be compatible with s-channel helicity conservation.

A search for single top quark production is performed in e^\pm p collisions at HERA. The search exploits data corresponding to an integrated luminosity of 118.3 pb^-1. A model for the anomalous production of top quarks in a flavour changing neutral current process involving a t-u-gamma coupling is investigated. Decays of top quarks into a b quark and a W boson are considered in the leptonic and the hadronic decay channels of the W. Both a cut-based analysis and a multivariate likelihood analysis are performed to discriminate anomalous top quark production from Standard Model background processes. In the leptonic channel, 5 events are found while 1.31 \pm 0.22 events are expected from the Standard Model background. In the hadronic channel, no excess above the expectation for Standard Model processes is found. These observations lead to a cross section \sigma (ep -> e t X) = 0.29 +0.15 -0.14 pb at \sqrt{s} = 319 GeV. Alternatively, assuming that the observed events are due to a statistical fluctuation, upper limits of 0.55 pb on the anomalous top production cross section and of 0.27 on the t-u-gamma coupling \kappa_{t-u-gamma} are established at the 95% confidence level.

We present a new simulation engine for fast generation of ultra-high energy cosmic ray data based on parametrizations of common assumptions of UHECR origin and propagation. Implemented are deflections in unstructured turbulent extragalactic fields, energy losses for protons due to photo-pion production and electron-pair production, as well as effects from the expansion of the universe. Additionally, a simple model to estimate propagation effects from iron nuclei is included. Deflections in the Galactic magnetic field are included using a matrix approach with precalculated lenses generated from backtracked cosmic rays. The PARSEC program is based on object oriented programming paradigms enabling users to extend the implemented models and is steerable with a graphical user interface.

In order to interpret cosmic ray observations, detailed modeling of propagation effects invoking all important messengers is necessary. We introduce a new photon production and propagation code as an inherent part of the CRPropa 3 software framework. By implementing additional photon production channels, which are important for energies below ∼ 1018 eV, this code can be used for multi-messenger studies connecting the TeV and sub EeV energy regime and for interpreting models of ultra-high energy cosmic ray sources. We discuss the importance of the individual production channels and propagation effects and present example applications.

AMIGA (Auger Muons and Infill for the Ground Array) is an upgrade of the Pierre Auger Observatory to complement the study of ultra-high-energy cosmic rays (UHECR) by measuring the muon content of extensive air showers (EAS). It consists of an array of 61 water Cherenkov detectors on a denser spacing in combination with underground scintillation detectors used for muon density measurement. Each detector is composed of three scintillation modules, with 10 m$^2$ detection area per module, buried at 2.3 m depth, resulting in a total detection area of 30 m$^2$. Silicon photomultiplier sensors (SiPM) measure the amount of scintillation light generated by charged particles traversing the modules. In this paper, the design of the front-end electronics to process the signals of those SiPMs and test results from the laboratory and from the Pierre Auger Observatory are described. Compared to our previous prototype, the new electronics shows a higher performance, higher efficiency and lower power consumption, and it has a new acquisition system with increased dynamic range that allows measurements closer to the shower core. The new acquisition system is based on the measurement of the total charge signal that the muonic component of the cosmic ray shower generates in the detector.

Photoproduction of 2-jet events is studied with the H1 detector at HERA. Parton cross sections are extracted from the data by an unfolding method using leading order parton-jet correlations of a QCD generator. The gluon distribution in the photon is derived in the fractional momentum range 0.04 ⩽ xγ ⩽ 1 at the average factorization scale 75 GeV2.

The ratio of the deuteron to proton structure functions is measured at very small Bjorken $x$ (down to 1${0}^{--6}$) and for ${Q}^{2}&gt;0.001$ Ge${\mathrm{V}}^{2}$ from scattering of 470 GeV muons on liquid hydrogen and deuterium targets. The ratio ${F}_{2}^{n}{/F}_{2}^{p}$ extracted from these measurements is found to be constant, at a value of $0.935\ifmmode\pm\else\textpm\fi{}0.008\ifmmode\pm\else\textpm\fi{}0.034$, for $x&lt;0.01$. This result suggests the presence of nuclear shadowing effects in the deuteron. The dependence of the ratio on ${Q}^{2}$ is also examined; no significant variation is found.

The cross section of the charged current process e−p → ve + hadrons is measured at HERA for transverse momenta of the hadron system larger than 25 GeV. The size of the cross section exhibits the W propagator.

We present a study of Jψ meson production in collisions of 26.7 GeV electrons with 820 GeV protons, performed with the H1-detector at the HERA collider at DESY. The Jψ mesons are detected via their leptonic decays both to electrons and muons. Requiring exactly two particles in the detector, a cross section of σ(ep → JψX) = (8.8±2.0±2.2) nb is determined for 30 GeV ≤ Wγp ≤ 180 GeV and Q2 ≲ 4 GeV2. Using the flux of quasi-real photons with Q2 ≲ 4 GeV2, a total production cross section of σ(γp → J/ψX) = (56±13±14) nb is derived at an average Wγp=90 GeV. The distribution of the squared momentum transfer t from the proton to the Jψ can be fitted using an exponential exp(−b∥t∥) below a ∥t∥ of 0.75 GeV2 yielding a slope parameter of b = (4.7±1.9) GeV−2.

A search for leptoquarks at HERA was performed in H1 using 1994 e+ p data corresponding to an integrated luminosity of about 3 pb−1. Single leptoquarks were searched for in direct positron-quark fusion processes taking into account possible decays into lepton-quark pairs of either the first, the second, or the third generation. No significant deviation from the Standard Model predictions is found in the various final states studied and mass dependent exclusion limits are derived on the Yukawa couplings of the leptoquarks. Compared with earlier results from an analysis of e− p data, exclusion limits are considerably improved for leptoquarks which could be produced via e+ -valence quark fusion. For leptoquarks with lepton flavour conserving couplings, masses up to 275 GeV (depending on the leptoquark type) are excluded for coupling values larger than 4πλem. For leptoquarks with lepton flavour violating couplings, masses up to 225 GeV are excluded for couplings with leptons of the second or third generation larger than 4πλem. Fourteen possible combinations of couplings are studied and stringent exclusion limits comparable or better than any existing direct or indirect limits are obtained for each leptoquark type.

A model-independent search for deviations from the Standard Model prediction is performed in e+p and e−p collisions at HERA using H1 data corresponding to an integrated luminosity of 117pb−1. For the first time all event topologies involving isolated electrons, photons, muons, neutrinos and jets with high transverse momenta are investigated in a single analysis. Events are assigned to exclusive classes according to their final state. A statistical algorithm is developed to search for deviations from the Standard Model in the distributions of the scalar sum of transverse momenta or invariant mass of final state particles and to quantify their significance. A good agreement with the Standard Model prediction is observed in most of the event classes. The most significant deviation is found for a topology containing an isolated muon, missing transverse momentum and a jet, consistent with a previously reported observation.

A search for events with a high-energy isolated electron or muon and missing transverse momentum has been performed at the electron–proton collider HERA using an integrated luminosity of 13.6 pb−1 in e−p scattering and 104.7 pb−1 in e+p scattering. Within the Standard Model such events are expected to be mainly due to W boson production with subsequent leptonic decay. In e−p interactions one event is observed in the electron channel and none in the muon channel, consistent with the expectation of the Standard Model. In the e+p data a total of 18 events are seen in the electron and muon channels compared to an expectation of 12.4±1.7 dominated by W production (9.4±1.6). Whilst the overall observed number of events is broadly in agreement with the number predicted by the Standard Model, there is an excess of events with transverse momentum of the hadronic system greater than 25 GeV with 10 events found compared to 2.9±0.5 expected. The results are used to determine the cross-section for events with an isolated electron or muon and missing transverse momentum.

Perceptual quality and food safety of grape products like wine is generally impaired by grape rot. Commonly applied visual inspection for quality assessment remains subjective. However, conventional analytical determinations are tedious and time-consuming. In contrast, near infrared/visible (NIR/VIS) spectroscopy is an objective and rapid alternative. An industrial spectrometer especially designed for on-line process integration was applied in laboratory configuration to evaluate the feasibility of the prediction of ergosterol and 12 further quality-associated parameters in grape mashes. Calibration models were established, validated, and evaluated. Spectral ranges used were 450–850 nm (VIS) and 1050–1650 nm (NIR). The regression method applied was partial least squares (PLS) regression. Calibrations at best suitable for discriminating low and high values were obtained for gluconic, acetic, tartaric, and titratable acids contents, pH value, ethanol content, and laccase activity. Therefore, for these parameters limits of NIR/VIS spectroscopy may be revealed. Calibrations for semi-quantitative predictions or rough estimations were obtained for fructose, glucose, and malic acid contents. Best performance suitable for quantitative predictions was achieved for relative density, glycerol, and ergosterol contents. The industrial spectrometer proved to perform similar to a research laboratory spectrometer. Consequently, a future on-line implementation of NIR/VIS spectrometers in wineries may be a valuable and reliable tool for rapid grape quality assessment at reception. Particularly, ergosterol content prediction proved to be a promising measure for efficient and immediate quality control and management, respectively. Wine quality and food safety may be increased. Fair and incentive pricing of delivered grapes may be enabled.

The influence of droplet size on the antioxidant activity of oil-in-water emulsions loaded with rosemary extract in mixed emulsion systems was investigated.

Abstract Simultaneous measurements of air showers with the fluorescence and surface detectors of the Pierre Auger Observatory allow a sensitive search for EeV photon point sources. Several Galactic and extragalactic candidate objects are grouped in classes to reduce the statistical penalty of many trials from that of a blind search and are analyzed for a significant excess above the background expectation. The presented search does not find any evidence for photon emission at candidate sources, and combined p -values for every class are reported. Particle and energy flux upper limits are given for selected candidate sources. These limits significantly constrain predictions of EeV proton emission models from non-transient Galactic and nearby extragalactic sources, as illustrated for the particular case of the Galactic center region.

Meat products enriched with n-3 fatty acids are highly susceptible to lipid oxidation. Therefore, the purpose of this study was to retard lipid oxidation by oil-in-water emulsions (10% (w/w) Miglyol 812 N, 2% (w/w) Tween 80) loaded with rosemary extract and to evaluate the impact of droplet size (d43 = 190–5700 nm) in cooked emulsion-type sausages containing 1% encapsulated fish oil (10% (w/w) oil, 2% (w/w) Tween 80). Mechanically prepared emulsions were physically stable during the 35-day study and neither coalescence nor Ostwald ripening occurred. Moreover, the Miglyol oil-in-water emulsion without incorporated antioxidant (o/wcontrol) was slightly flocculated. The oxidative stability of the sausages containing 50 mg/kg encapsulated rosemary extract improved significantly compared to the control sausages during the first 21 days stored at 7 °C. However, from day 21–35, the primary and secondary oxidation products increased significantly in the sausages with incorporated antioxidants, concurrently no differences in the antioxidant effectiveness of differently sized emulsions loaded with rosemary extract were observed for thiobarbituric acid reactive substances, propanal and hexanal. Consequently, there is no need for the industry to decrease the droplet size of oil-in-water emulsions loaded with rosemary extract to enhance the oxidative stability of these products.

We investigate two recent parameterizations of the galactic magnetic field with respect to their impact on cosmic nuclei traversing the field. We present a comprehensive study of the size of angular deflections, dispersion in the arrival probability distributions, multiplicity in the images of arrival on Earth, variance in field transparency, and influence of the turbulent field components. To remain restricted to ballistic deflections, a cosmic nucleus with energy E and charge Z should have a rigidity above E/Z=6 EV. In view of the differences resulting from the two field parameterizations as a measure of current knowledge in the galactic field, this rigidity threshold may have to be increased. For a point source search with E/Z ≥ 60 EV, field uncertainties increase the required signal events for discovery moderately for sources in the northern and southern regions, but substantially for sources near the galactic disk.

The direct measurement of the top quark-Higgs coupling is one of the important questions in understanding the Higgs boson. The coupling can be obtained through measurement of the top quark pair-associated Higgs boson production cross-section. Of the multiple challenges arising in this cross-section measurement, we investigate the reconstruction of the partons originating from the hard scattering process using the measured jets in simulated tH events. The task corresponds to an assignment challenge of m objects (jets) to n other objects (partons), where m≥ n. We compare several methods with emphasis on a concept based on deep learning techniques which yields the best results with more than 50% of correct jet-parton assignments.

Ultra-high energy cosmic rays can be measured through the detection of radio-frequency radiation from air showers. The radio-frequency emission originates from deflections of the air-shower particles in the geomagnetic field and from a time-varying negative charge excess in the shower front. The distribution of the radio signal on the ground contains information on crucial cosmic-ray properties, such as energy and mass. A long standing challenge is to access this information experimentally with a sparse grid of antennas. We present a new analytic model of the radio signal distribution that depends only on the definition of the shower axis and on the parameters energy and distance to the emission region. The distance to the emission region has a direct relation to the cosmic ray's mass. This new analytic model describes the different polarizations of the radiation and therefore allows the use of independently measured signals in different polarization, thereby doubling the amount of information that is available in current radio arrays, compared to what has been used thus far. We show with the use of CoREAS Monte Carlo simulation that fitting the measurements with our model does not result in significant contributions in both systematic bias and in resolution for the extracted parameters energy and distance to emission region, when compared to the expected experimental measurement uncertainties.

We present a new approach for the identification of ultra-high energy cosmic rays from sources using dynamic graph convolutional neural networks. These networks are designed to handle sparsely arranged objects and to exploit their short- and long-range correlations. Our method searches for patterns in the arrival directions of cosmic rays, which are expected to result from coherent deflections in cosmic magnetic fields. The network discriminates astrophysical scenarios with source signatures from those with only isotropically distributed cosmic rays and allows for the identification of cosmic rays that belong to a deflection pattern. We use simulated astrophysical scenarios where the source density is the only free parameter to show how density limits can be derived. We apply this method to a public data set from the AGASA Observatory.

The reaction e+p→e+X is studied with the H1 detector at Hera. The data cover momentum transfers Q2 between 200GeV2 and 30000GeV2 and correspond to an integrated luminosity of 35.6pb−1. The differential cross section dσ/dQ2 is compared to the Standard Model expectation for neutral current scattering and analysed to search for (ēe)(q̄q) contact interactions. No evidence for new phenomena is observed. The results are used to set limits on scales within models of electron–quark compositeness, quark form factors and the exchange of virtual heavy leptoquarks. A search for gravitational effects mediated through the exchange of virtual gravitons which propagate into large extra dimensions is presented.

Using the H1 detector at HERA, charged particle multiplicity distributions in deep inelastice + p scattering have been measured over a large kinematical region. The evolution withW andQ 2 of the multiplicity distribution and of the multiplicity moments in pseudorapidity domains of varying size is studied in the current fragmentation region of the hadronic centre-of-mass frame. The results are compared with data from fixed target lepton-nucleon interactions,e + e − annihilations and hadron-hadron collisions as well as with expectations from QCD based parton models. Fits to the Negative Binomial and Lognormal distributions are presented.

Properties of the hadronic final state in photoproduction events with large transverse energy are studied at the electron-proton collider HERA. Distributions of the transverse energy, jets and underlying event energy are compared to % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWexLMBb50ujb% qeguuDJXwAKbacfiGaf8hCaaNbaebacqWFWbaCaaa!3DB7! $$\bar pp$$ data and QCD calculations. The comparisons show that theγp events can be consistently described by QCD models including — in addition to the primary hard scattering process — interactions between the two beam remnants. The differential jet cross sectionsdσ/dE T jet anddσ/dη jet are measured.

A search for scalar and vector leptoquarks coupling to first generation fermions is performed using the e+p and e−p scattering data collected by the H1 experiment between 1994 and 2000. The data correspond to a total integrated luminosity of 117pb−1. No evidence for the direct or indirect production of such particles is found in data samples with a large transverse momentum final state electron or with large missing transverse momentum. Constraints on leptoquark models are established. For leptoquark couplings of electromagnetic strength, leptoquarks with masses up to 275–325GeV are ruled out at 95% confidence level. These limits improve and supercede earlier H1 limits based on subsamples of the data used here.

Dijet production in deep inelastic ep scattering is investigated in the region of low values of the Bjorken-variable x (10 -4 < x < 10 -2 ) and low photon virtualities Q 2 (5 < Q 2 < 100 GeV 2 ).The measured dijet cross sections are compared with perturbative QCD calculations in next-to-leading order.For most dijet variables studied, these calculations can provide a reasonable description of the data over the full phase space region covered, including the region of very low x.However, large discrepancies are observed for events with small separation in azimuth between the two highest transverse momentum jets.This region of phase space is described better by predictions based on the CCFM evolution equation, which incorporates k t factorized unintegrated parton distributions.A reasonable description is also obtained using the Color Dipole Model or models incorporating virtual photon structure.

Experiments in high silica systems at temperatures close to the solidus often produce crystals and melt pools that are too small for in situ analysis. Oscillating the temperature during an experimental run speeds up recrystallization of magma by dissolving small and increasing the size of larger crystals, dramatically changing the crystal size distribution. This principle of periodic heating and cooling, caused for example by repeated injection of hot magma, is also a potential acceleration for the formation of phenocrystic textures in natural rocks.

At oceanic spreading centers, interactions between magma and hydrothermal convecting systems trigger major physical, thermal, and chemical exchanges. The two-pyroxene hornfels recovered from the base of the sheeted dike sequence at Integrated Ocean Drilling Program (IODP) Site 1256 (equatorial Eastern Pacific) are interpreted as a conducting boundary layer between the underlying axial melt lens and the hydrothermally cooled sheeted dikes. They are cut by numerous small, felsic veins, which were recently interpreted as a product of hydrous partial melting of sheeted dikes. Here, we present trace element compositions of products (melts and residues) of hydrous partial melting experiments using basalts and hornfels from IODP Site 1256 as starting material. The experimental products generated between 910 °C and 970 °C match the natural lithologies from Site 1256 in terms of major and trace element compositions. The compositions of the anatectic melts correspond to the compositions of the felsic veins, while the residual minerals match the compositions of the two-pyroxene hornfels, evidencing that hydrous partial melting is an important magmatic process in the gabbro/dike transition of fast-spreading mid-oceanic ridges. Our results complement previous experimental studies on anatectic processes occurring at the roof of the magma chambers from fast-spreading mid-ocean ridges. Moreover, calculations of mixing and assimilation fractional crystallization using the experimental partial melts as contaminant/assimilant showed that anatectic melts can only be a minor contributor to the contamination process.

Abstract The reconstruction of cosmic ray-induced air showers from measurements of radio waves constitutes a major challenge. In this work, we focus on recovering the full three-dimensional electromagnetic field from two recorded signal traces of an antenna station covering two horizontal polarization directions. The simulated field is folded by a direction and frequency-dependent characteristic antenna response pattern, resulting in voltage signal traces as a function of time. Both signal traces are contaminated by simulated background noise. We use conditional Invertible Neural Networks (cINNs) to learn posterior distributions, from which the most likely electromagnetic field given a measured signal trace can be inferred. To improve robustness, we extend the method with an autoencoder by reducing the parameter phase space and decoupling the cINN from specific data shapes. Thereby, each signal trace is condensed into a small number of abstract parameters in the latent space on which the cINN operates. The presented method shows promising results and can be transferred to other unfolding problems where the recovery of the pre-measurement state is of interest.

Research on Universe and Matter (ErUM), conducted at major infrastructures such as CERN and large observatories in collaboration with university groups, plays an important role in driving the digital transformation for the future. The German action plan "ErUM-Data" [2] promotes this transformation through the interdisciplinary networking and financial support of about 20.000 scientists. The ErUM-Data-Hub [4] serves as a central networking and transfer office to meet these ambitions. One central task is designing, organizing and performing schools and workshops for young and expert scientists in the areas of big data, deep learning, sustainable computing and many more. We present the achievements up to the first anniversary of the ErUM-Data-Hub in the German ErUM community.

The continuous growth in model complexity in high-energy physics (HEP) collider experiments demands increasingly time-consuming model fits. We show first results on the application of conditional invertible networks (cINNs) to this challenge. Specifically, we construct and train a cINN to learn the mapping from signal strength modifiers to observables and its inverse. The resulting network infers the posterior distribution of the signal strength modifiers rapidly and for low computational cost. We present performance indicators of such a setup including the treatment of systematic uncertainties. Additionally, we highlight the features of cINNs estimating the signal strength for a vector boson associated Higgs production analysis of simulated samples of events, which include a simulation of the CMS detector.

The usage of Deep Neural Networks (DNNs) as multi-classifiers is widespread in modern HEP analyses. In standard categorisation methods, the high-dimensional output of the DNN is often reduced to a one-dimensional distribution by exclusively passing the information about the highest class score to the statistical inference method. Correlations to other classes are hereby omitted. Moreover, in common statistical inference tools, the classification values need to be binned, which relies on the researcher’s expertise and is often nontrivial. To overcome the challenge of binning multiple dimensions and preserving the correlations of the event-related classification information, we perform K-means clustering on the high-dimensional DNN output to create bins without marginalising any axes. We evaluate our method in the context of a simulated cross section measurement at the CMS experiment, showing an increased expected sensitivity over the standard binning approach.

Single particles and jets in deeply inelastic scattering at low x are measured with the H1 detector in the region away from the current jet and towards the proton remnant, known as the forward region. Hadronic final state measurements in this region are expected to be particularly sensitive to QCD evolution effects. Jet cross-sections are presented as a function of Bjorken-x for forward jets produced with a polar angle to the proton direction, theta, in the range 7 < theta < 20 degrees. Azimuthal correlations are studied between the forward jet and the scattered lepton. Charged and neutral single particle production in the forward region are measured as a function of Bjorken-x, in the range 5 < theta < 25 degrees, for particle transverse momenta larger than 1 GeV. QCD based Monte Carlo predictions and analytical calculations based on BFKL, CCFM and DGLAP evolution are compared to the data. Predictions based on the DGLAP approach fail to describe the data, except for those which allow for a resolved photon contribution.

Events with no hadronic energy flow in a large interval of pseudo-rapidity in the proton direction are observed in photon-proton interactions at an average centre of mass energy 〈√sγp〉 of 200 GeV These events are interpreted as photon diffractive dissociation. Evidence for hard scattering in photon diffractive dissociation is demonstrated using inclusive single particle spectra, thrust as a function of transverse energy, and the observation of jet production. The data can be described by a Monte Carlo calculation including hard photon-pomeron scattering.

Deep inelastic e p scattering data, taken with the H1 detector at HERA, are used to study the event shape variables thrust, jet broadening and jet mass in the current hemisphere of the Breit frame over a large range of momentum transfers Q between 7 GeV and 100 GeV. The data are compared with results from e+e− experiments. Using second order QCD calculations and an approach to relate hadronisation effects to power corrections an analysis of the Q dependences of the means of the event shape parameters is presented, from which both the power corrections and the strong coupling constant are determined without any assumption on fragmentation models. The power corrections of all event shape variables investigated follow a 1/Q behaviour and can be described by a common parameter α0.

A measurement of inclusive jet cross-sections in deep-inelastic ep scattering at HERA is presented based on data with an integrated luminosity of 21.1 pb−1. The measurement is performed for photon virtualities Q2 between 5 and 100 GeV2, differentially in Q2, in the jet transverse energy ET, in ET2/Q2 and in the pseudorapidity ηlab. With the renormalization scale μR=ET, perturbative QCD calculations in next-to-leading order (NLO) give a good description of the data in most of the phase space. Significant discrepancies are observed only for jets in the proton beam direction with ET below 20 GeV and Q2 below 20 GeV2. This corresponds to the region in which NLO corrections are largest and further improvement of the calculations is thus of particular interest.

In this paper the spectrometer constructed by the E665 Collaboration is described. The spectrometer was built during the period 1982–87 and the first data were taken during the 1987–88 Fixed Target run of the Fermi National Accelerator Laboratory (FNAL) Tevatron. This is the first of a series of runs in which a comprehensive program of high energy muon scattering experiments will be performed.

We report a multi-resolution search for anisotropies in the arrival directions of cosmic rays detected at the Pierre Auger Observatory with local zenith angles up to 80o and energies in excess of 4 EeV (4 × 1018 eV). This search is conducted by measuring the angular power spectrum and performing a needlet wavelet analysis in two independent energy ranges. Both analyses are complementary since the angular power spectrum achieves a better performance in identifying large-scale patterns while the needlet wavelet analysis, considering the parameters used in this work, presents a higher efficiency in detecting smaller-scale anisotropies, potentially providing directional information on any observed anisotropies. No deviation from isotropy is observed on any angular scale in the energy range between 4 and 8 EeV. Above 8 EeV, an indication for a dipole moment is captured; while no other deviation from isotropy is observed for moments beyond the dipole one. The corresponding p-values obtained after accounting for searches blindly performed at several angular scales, are 1.3 × 10−5 in the case of the angular power spectrum, and 2.5 × 10−3 in the case of the needlet analysis. While these results are consistent with previous reports making use of the same data set, they provide extensions of the previous works through the thorough scans of the angular scales.

Machine learning has been applied to several problems in particle physics research, beginning with applications to high-level physics analysis in the 1990s and 2000s, followed by an explosion of applications in particle and event identification and reconstruction in the 2010s. In this document we discuss promising future research and development areas for machine learning in particle physics. We detail a roadmap for their implementation, software and hardware resource requirements, collaborative initiatives with the data science community, academia and industry, and training the particle physics community in data science. The main objective of the document is to connect and motivate these areas of research and development with the physics drivers of the High-Luminosity Large Hadron Collider and future neutrino experiments and identify the resource needs for their implementation. Additionally we identify areas where collaboration with external communities will be of great benefit.

The profile of the longitudinal development of showers produced by ultra-high energy cosmic rays carries information related to the interaction properties of the primary particles with atmospheric nuclei. In this work, we present the first measurement of the average shower profile in traversed atmospheric depth at the Pierre Auger Observatory. The shapes of profiles are well reproduced by the Gaisser-Hillas parametrization within the range studied, for E > 10^{17.8} eV. A detailed analysis of the systematic uncertainties is performed using 10 years of data and a full detector simulation. The average shape is quantified using two variables related to the width and asymmetry of the profile, and the results are compared with predictions of hadronic interaction models for different primary particles.

Inelastic scattering of 490 GeV μ+ from deuterium and xenon nuclei has been studied for xBj>s.001. The ratio of the xenon/deuterium cross section per nucleon is observed to vary with xBj, with a depletion in the kinematic range 0.001 < xBj < 0.025 which exhibits no significant Q2 dependence. An electromagnetic calorimeter was used to verify the radiative corrections.