W. Lange

The first measurement of lepton-jet momentum imbalance and azimuthal correlation in lepton-proton scattering at high momentum transfer is presented. These data, taken with the H1 detector at HERA, are corrected for detector effects using an unbinned machine learning algorithm (multifold), which considers eight observables simultaneously in this first application. The unfolded cross sections are compared with calculations performed within the context of collinear or transverse-momentum-dependent factorization in quantum chromodynamics as well as Monte Carlo event generators.

Inclusive $$ep$$ double differential cross sections for neutral current deep inelastic scattering are measured with the H1 detector at HERA. The data were taken with a lepton beam energy of $$27.6$$ GeV and two proton beam energies of $$E_p=460$$ and 575 GeV corresponding to centre-of-mass energies of 225 and 252 GeV, respectively. The measurements cover the region of $$6.5\times 10^{-4} \le x \le 0.65$$ for $$35\le Q^2 \le 800$$ GeV $$^2$$ up to $$y=0.85$$ . The measurements are used together with previously published H1 data at $$E_p=920$$ GeV and lower $$Q^2$$ data at $$E_p=460$$ , $$575$$ and $$920$$ GeV to extract the longitudinal proton structure function $$F_L$$ in the region $$1.5\le Q^2 \le 800$$ GeV $$^2$$ .

A BSTRACT Inclusive e ± p single and double differential cross sections for neutral and charged current deep inelastic scattering processes are measured with the H1 detector at HERA. The data were taken at a centre-of-mass energy of $ \sqrt {s} = {319} $ GeV with a total integrated luminosity of 333.7 pb −1 shared between two lepton beam charges and two longitudinal lepton polarisation modes. The differential cross sections are measured in the range of negative four-momentum transfer squared, Q 2 , between 60 and 50 000 GeV 2 , and Bjorken x between 0 . 0008 and 0 . 65. The measurements are combined with earlier published unpolarised H1 data to improve statistical precision and used to determine the structure function $ xF_{3}^{{\gamma Z}} $ . Ameasurementoftheneutralcurrentparityviolating structure function $ F_{2}^{{\gamma Z}} $ is presented for the first time. The polarisation dependence of the charged current total cross section is also measured. The new measurements are well described by a next-to-leading order QCD fit based on all published H1 inclusive cross section data which are used to extract the parton distribution functions of the proton.

Progress in experimental particle physics in the coming decade depends crucially upon the ability to carry out experiments in high-radiation areas. In order to perform these complex and expensive experiments, new radiation hard technologies must be developed. This paper discusses the use of diamond detectors in future tracking applications and their survivability in the highest radiation environments. We present results of devices constructed with the newest polycrystalline and single crystal Chemical Vapor Deposition diamond and their tolerance to radiation.

Abstract Charged particle multiplicity distributions in positron-proton deep inelastic scattering at a centre-of-mass energy $$\sqrt{s}=319$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>319</mml:mn> </mml:mrow> </mml:math> GeV are measured. The data are collected with the H1 detector at HERA corresponding to an integrated luminosity of 136 pb $$^{-1}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow /> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> . Charged particle multiplicities are measured as a function of photon virtuality $$Q^2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>Q</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:math> , inelasticity y and pseudorapidity $$\eta $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>η</mml:mi> </mml:math> in the laboratory and the hadronic centre-of-mass frames. Predictions from different Monte Carlo models are compared to the data. The first and second moments of the multiplicity distributions are determined and the KNO scaling behaviour is investigated. The multiplicity distributions as a function of $$Q^2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>Q</mml:mi> <mml:mn>2</mml:mn> </mml:msup> </mml:math> and the Bjorken variable $$x_{\mathrm{bj}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>x</mml:mi> <mml:mi>bj</mml:mi> </mml:msub> </mml:math> are converted to the hadron entropy $$S_{\mathrm{hadron}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>S</mml:mi> <mml:mi>hadron</mml:mi> </mml:msub> </mml:math> , and predictions from a quantum entanglement model are tested.

The application of diamond for the detection of charged particles in atomic, nuclear and high-energy physics experiments is described. We compare the properties of three undoped diamond types, all of them produced by Chemical Vapor Deposition (CVD), in particular homoepitaxial single-crystal CVD Diamond (scCVDD), polycrystalline CVD Diamond (pcCVDD) grown on silicon, and CVD Diamond on Iridium (DoI) grown on the multi-layer substrate Ir/YSZ/Si001. The characteristics of the transient current (TC) signals generated from 241Am-α-particles in the samples are exploited to evaluate the potential of the diamond crystals for particle timing and spectroscopy applications. The TC technique (TCT) results are correlated to the dark conductivity and the structural defects of the bulk materials as well as to the morphology and roughness of the diamond surfaces. The deterioration of the sensors performance after heavy irradiations with 26 MeV protons, 20 MeV neutrons, and 10 MeV electrons is discussed by means of charge-collection efficiency results, TC technique, and optical absorption spectroscopy (OAS). The important role of the diamond signal processing is underlined, which influences both the quality of the CVDD characterization data as well as the in-beam performance of the diamond sensors.

Two special calorimeters are foreseen for the instrumentation of the very forward region of the ILC detector, a luminometer designed to measure the rate of low angle Bhabha scattering events with a precision better than 10−3 and a low polar angle calorimeter, adjacent to the beam-pipe. The latter will be hit by a large amount of beamstrahlung remnants. The amount and shape of these depositions will allow a fast luminosity estimate and the determination of beam parameters. The sensors of this calorimeter must be radiation hard. Both devices will improve the hermeticity of the detector in the search for new particles. Finely segmented and very compact calorimeters will match the requirements. Due to the high occupancy fast front-end electronics is needed. The design of the calorimeters developed and optimised with Monte Carlo simulations is presented. Sensors and readout electronics ASICs have been designed and prototypes are available. Results on the performance of these major components are summarised.

Inclusive production of D* mesons in deep-inelastic ep scattering at HERA is studied in the range 5 < Q^2 <100 GeV^2 of the photon virtuality and 0.02 < y < 0.7 of the inelasticity of the scattering process. The observed phase space for the D* meson is p_T(D*) > 1.25 GeV and |eta(D*)| < 1.8. The data sample corresponds to an integrated luminosity of 348 pb^{-1} collected with the H1 detector. Single and double differential cross sections are measured and the charm contribution F_2^{ccbar} to the proton structure function F_2 is determined. The results are compared to perturbative QCD predictions at next-to-leading order implementing different schemes for the charm mass treatment and with Monte Carlo models based on leading order matrix elements with parton showers.

Abstract A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities $$5.5&lt;Q^2 &lt;80\,\mathrm {GeV}^2 $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>5.5</mml:mn><mml:mo>&lt;</mml:mo><mml:msup><mml:mi>Q</mml:mi><mml:mn>2</mml:mn></mml:msup><mml:mo>&lt;</mml:mo><mml:mn>80</mml:mn><mml:mspace /><mml:msup><mml:mrow><mml:mi>GeV</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msup></mml:mrow></mml:math> and inelasticities $$0.2&lt;y&lt;0.6$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>0.2</mml:mn><mml:mo>&lt;</mml:mo><mml:mi>y</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.6</mml:mn></mml:mrow></mml:math> is presented, using data taken with the H1 detector at HERA, corresponding to an integrated luminosity of $$290\,\mathrm {pb}^{-1}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>290</mml:mn><mml:mspace /><mml:msup><mml:mrow><mml:mi>pb</mml:mi></mml:mrow><mml:mrow><mml:mo>-</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math> . Double-differential inclusive jet, dijet and trijet cross sections are measured simultaneously and are presented as a function of jet transverse momentum observables and as a function of $$Q^2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi>Q</mml:mi><mml:mn>2</mml:mn></mml:msup></mml:math> . Jet cross sections normalised to the inclusive neutral current DIS cross section in the respective $$Q^2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi>Q</mml:mi><mml:mn>2</mml:mn></mml:msup></mml:math> -interval are also determined. Previous results of inclusive jet cross sections in the range $$150&lt;Q^2 &lt;15{,}000\,\mathrm {GeV}^2 $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>150</mml:mn><mml:mo>&lt;</mml:mo><mml:msup><mml:mi>Q</mml:mi><mml:mn>2</mml:mn></mml:msup><mml:mo>&lt;</mml:mo><mml:mn>15</mml:mn><mml:mo>,</mml:mo><mml:mn>000</mml:mn><mml:mspace /><mml:msup><mml:mrow><mml:mi>GeV</mml:mi></mml:mrow><mml:mn>2</mml:mn></mml:msup></mml:mrow></mml:math> are extended to low transverse jet momenta $$5&lt;P_\mathrm{T}^\mathrm{jet} &lt;7\,\mathrm {GeV} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>5</mml:mn><mml:mo>&lt;</mml:mo><mml:msubsup><mml:mi>P</mml:mi><mml:mrow><mml:mi>T</mml:mi></mml:mrow><mml:mi>jet</mml:mi></mml:msubsup><mml:mo>&lt;</mml:mo><mml:mn>7</mml:mn><mml:mspace /><mml:mi>GeV</mml:mi></mml:mrow></mml:math> . The data are compared to predictions from perturbative QCD in next-to-leading order in the strong coupling, in approximate next-to-next-to-leading order and in full next-to-next-to-leading order. Using also the recently published H1 jet data at high values of $$Q^2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mi>Q</mml:mi><mml:mn>2</mml:mn></mml:msup></mml:math> , the strong coupling constant $$\alpha _s(M_Z)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>α</mml:mi><mml:mi>s</mml:mi></mml:msub><mml:mrow><mml:mo>(</mml:mo><mml:msub><mml:mi>M</mml:mi><mml:mi>Z</mml:mi></mml:msub><mml:mo>)</mml:mo></mml:mrow></mml:mrow></mml:math> is determined in next-to-leading order.

A search for first generation scalar and vector leptoquarks produced in ep collisions is performed by the H1 experiment at HERA. The full H1 data sample is used in the analysis, corresponding to an integrated luminosity of 446 pb^-1. No evidence for the production of leptoquarks is observed in final states with a large transverse momentum electron or with large missing transverse momentum, and constraints on leptoquark models are derived. For leptoquark couplings of electromagnetic strength lambda=0.3, first generation leptoquarks with masses up to 800 GeV are excluded at 95% confidence level.

The cross section of the diffractive process e + p → e + Xp is measured at a centre-of-mass energy of 318 GeV, where the system X contains at least two jets and the leading final state proton p is detected in the H1 Very Forward Proton Spectrometer. The measurement is performed in photoproduction with photon virtualities Q 2 < 2 GeV2 and in deep-inelastic scattering with 4 GeV2 < Q 2 < 80 GeV2. The results are compared to next- to-leading order QCD calculations based on diffractive parton distribution functions as extracted from measurements of inclusive cross sections in diffractive deep-inelastic scattering.

The strong coupling constant αs is determined from inclusive jet and dijet cross sections in neutral-current deep-inelastic ep scattering (DIS) measured at HERA by the H1 collaboration using next-to-next-to-leading order (NNLO) QCD predictions. The dependence of the NNLO predictions and of the resulting value of αs(mZ) at the Z-boson mass mZ are studied as a function of the choice of the renormalisation and factorisation scales. Using inclusive jet and dijet data together, the strong coupling constant is determined to be αs(mZ)=0.1157(20)exp(29)th . Complementary, αs(mZ) is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value αs(mZ)=0.1142(28)tot obtained is consistent with the determination from jet data alone. The impact of the jet data on the PDFs is studied. The running of the strong coupling is tested at different values of the renormalisation scale and the results are found to be in agreement with expectations.

The construction and performance of two large coaxial cylindrical multiwire proportional chambers with cathode readout, denoted as Z-detector, forming the outer part of the L3 central tracking detector, are described. Three self-supporting cylinders of about 1 m length and 1 m diameter, constructed as a sandwich of Kapton foil and foam, form the mechanical frame. In each chamber one cathode layer is subdivided into helical strips and the other one in rings. The readout of the charges induced on the cathode strips provides the avalanche position along the beam (z) direction. The detector has been running in the L3 experiment at LEP for nearly two years. The resolution of the z-measurement is 320 μm, the double track resolution is 10 mm. The efficiency of each chamber is 96%.

The diffractive process ep \rightarrow eXY, where Y denotes a proton or its low mass excitation with MY < 1.6 GeV, is studied with the H1 experiment at HERA. The analysis is restricted to the phase space region of the photon virtuality 3 \leq Q2 \leq 1600 GeV2, the square of the four-momentum transfer at the proton vertex |t| < 1.0 GeV2 and the longitudinal momentum fraction of the incident proton carried by the colourless exchange xIP < 0.05. Triple differential cross sections are measured as a function of xIP, Q2 and beta = x/xIP where x is the Bjorken scaling variable. These measurements are made after selecting diffractive events by demanding a large empty rapidity interval separating the final state hadronic systems X and Y . High statistics measurements covering the data taking periods 1999-2000 and 2004-2007 are combined with previously published results in order to provide a single set of diffractive cross sections from the H1 experiment using the large rapidity gap selection method. The combined data represent a factor between three and thirty increase in statistics with respect to the previously published results. The measurements are compared with predictions from NLO QCD calculations based on diffractive parton densities and from a dipole model. The proton vertex factorisation hypothesis is tested.

A compact and finely grained sandwich calorimeter is designed to instrument the very forward region of a detector at a future e+e− collider. The calorimeter will be exposed to low energy e+e− pairs originating from beamstrahlung, resulting in absorbed doses of about one MGy per year. GaAs pad sensors interleaved with tungsten absorber plates are considered as an option for this calorimeter. Several Cr-doped GaAs sensor prototypes were produced and irradiated with 8.5–10 MeV electrons up to a dose of 1.5 MGy. The sensor performance was measured as a function of the absorbed dose.

The cross section of diffractive deep-inelastic scattering ep \rightarrow eXp is measured, where the system X contains at least two jets and the leading final state proton is detected in the H1 Forward Proton Spectrometer. The measurement is performed for fractional proton longitudinal momentum loss xIP < 0.1 and covers the range 0.1 < |t| < 0.7 GeV2 in squared four-momentum transfer at the proton vertex and 4 < Q2 < 110 GeV2 in photon virtuality. The differential cross sections extrapolated to |t| < 1 GeV2 are in agreement with next-toleading order QCD predictions based on diffractive parton distribution functions extracted from measurements of inclusive and dijet cross sections in diffractive deep-inelastic scattering. The data are also compared with leading order Monte Carlo models.

Recueil des Travaux Chimiques des Pays-BasVolume 46, Issue 6 p. 417-429 Articles The poisoning of hydrogen electrodes. I A. H. W. Aten, A. H. W. Aten Amsterdam, The University, Laboratory for ElectrochemistrySearch for more papers by this authorP. Bruin, P. Bruin Amsterdam, The University, Laboratory for ElectrochemistrySearch for more papers by this authorW. de Lange, W. de Lange Amsterdam, The University, Laboratory for ElectrochemistrySearch for more papers by this author A. H. W. Aten, A. H. W. Aten Amsterdam, The University, Laboratory for ElectrochemistrySearch for more papers by this authorP. Bruin, P. Bruin Amsterdam, The University, Laboratory for ElectrochemistrySearch for more papers by this authorW. de Lange, W. de Lange Amsterdam, The University, Laboratory for ElectrochemistrySearch for more papers by this author First published: 1927 https://doi.org/10.1002/recl.19270460607Citations: 8AboutPDF 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 onFacebookTwitterLinked InRedditWechat Citing Literature Volume46, Issue61927Pages 417-429 RelatedInformation

The CMS Beam Conditions and Radiation Monitoring System, BRM, will support beam tuning, protect the CMS detector from adverse beam conditions, and measure the accumulated dose close to or inside all sub-detectors. It is composed of different sub-systems measuring either the particle flux near the beam pipe with time resolution between nano- and microseconds or the integrated dose over longer time intervals. This paper presents the Fast Beam Conditions Monitor, BCM1F, which is designed for fast flux monitoring measuring both beam halo and collision products. BCM1F is located inside the CMS pixel detector volume close to the beam-pipe. It uses sCVD diamond sensors and radiation hard front-end electronics, along with an analog optical readout of the signals. The commissioning of the system and its successful operation during the first beams of the LHC are described.

The very forward region of a detector at a linear e/sup +/e/sup -/ collider is a particularly challenging area for instrumentation. In the TESLA detector, two calorimeters, BeamCal (Beam Calorimeter) and LumiCal (Luminosity Calorimeter) are planned. The BeamCal is positioned just adjacent to the beampipe. It will be hit by beamstrahlung remnants giving a deposition of several tens of TeV per bunch crossing. The distribution of this energy will be measured to assist in tuning the beams. Single high-energy electrons will be identified and measured. High-energy electron identification is particularly important to veto backgrounds to new particle searches. Several technological options for BeamCal are discussed. Monte Carlo simulations are presented for a diamond/tungsten sandwich structure and compared to results obtained for a heavy element crystal calorimeter. First, tests of sensors are described. The LumiCal will measure larger polar angles than the BeamCal. It will provide a high-precision (O(10/sup -4/)) luminosity measurement from Bhabha scattering. Monte Carlo simulations to optimize the shape and the structure of the calorimeter are presented.

A search for physics beyond the Standard Model in neutral current deep inelastic scattering at high negative four-momentum transfer squared Q2 is performed in e±p collisions at HERA. The differential cross section dσ/dQ2, measured using the full H1 data sample corresponding to an integrated luminosity of 446pb−1, is compared to the Standard Model prediction. No significant deviation is observed. Limits on various models predicting new phenomena at high Q2 are derived. For general four-fermion eeqq contact interaction models, lower limits on the compositeness scale Λ are set in the range 3.6 TeV to 7.2 TeV. Leptoquarks with masses MLQ and couplings λ are constrained to MLQ/λ>0.41–1.86TeV and limits on squarks in R-parity violating supersymmetric models are derived. A lower limit on the gravitational scale in 4+n dimensions of MS>0.9TeV is established for low-scale quantum gravity effects in models with large extra dimensions. For the light quark radius an upper bound of Rq<0.65⋅10−18m is determined.

A measurement of the integrated luminosity at the ep collider HERA is presented, exploiting the elastic QED Compton process ep \rightarrow ep. The electron and the photon are detected in the backward calorimeter of the H1 experiment. The integrated luminosity of the data recorded in 2003 to 2007 is determined with a precision of 2.3%. The measurement is found to be compatible with the corresponding result obtained using the Bethe-Heitler process.

A measurement is presented of single- and double-differential dijet cross sections in diffractive deep-inelastic ep scattering at HERA using data collected by the H1 experiment corresponding to an integrated luminosity of 290 pb−1. The investigated phase space is spanned by the photon virtuality in the range of 4 < Q 2 < 100 GeV2 and by the fractional proton longitudinal momentum loss x ℙ < 0.03. The resulting cross sections are compared with next-to-leading order QCD predictions based on diffractive parton distribution functions and the value of the strong coupling constant is extracted.

A first measurement is presented of exclusive photoproduction of $$\rho ^0$$ mesons associated with leading neutrons at HERA. The data were taken with the H1 detector in the years 2006 and 2007 at a centre-of-mass energy of $$\sqrt{s}=319$$ GeV and correspond to an integrated luminosity of 1.16 pb $$^{-1}$$ . The $$\rho ^0$$ mesons with transverse momenta $$p_T<1$$ GeV are reconstructed from their decays to charged pions, while leading neutrons carrying a large fraction of the incoming proton momentum, $$x_L>0.35$$ , are detected in the Forward Neutron Calorimeter. The phase space of the measurement is defined by the photon virtuality $$Q^2 < 2$$ GeV $$^2$$ , the total energy of the photon–proton system $$20 < W_{\gamma p}< 100$$ GeV and the polar angle of the leading neutron $$\theta _n < 0.75$$ mrad. The cross section of the reaction $$\gamma p \rightarrow \rho ^0 n \pi ^+$$ is measured as a function of several variables. The data are interpreted in terms of a double peripheral process, involving pion exchange at the proton vertex followed by elastic photoproduction of a $$\rho ^0$$ meson on the virtual pion. In the framework of one-pion-exchange dominance the elastic cross section of photon-pion scattering, $$\sigma ^\mathrm{el}(\gamma \pi ^+ \rightarrow \rho ^0\pi ^+)$$ , is extracted. The value of this cross section indicates significant absorptive corrections for the exclusive reaction $$\gamma p \rightarrow \rho ^0 n \pi ^+$$ .

The Breit frame provides a natural frame to analyze lepton-proton scattering events. In this reference frame, the parton model hard interactions between a quark and an exchanged boson defines the coordinate system such that the struck quark is back-scattered along the virtual photon momentum direction. In Quantum Chromodynamics (QCD), higher order perturbative or non-perturbative effects can change this picture drastically. As Bjorken-$x$ decreases below one half, a rather peculiar event signature is predicted with increasing probability, where no radiation is present in one of the two Breit-frame hemispheres and all emissions are to be found in the other hemisphere. At higher orders in $\alpha_s$ or in the presence of soft QCD effects, predictions of the rate of these events are far from trivial, and that motivates measurements with real data. We report on the first observation of the empty current hemisphere events in electron-proton collisions at the HERA collider using data recorded with the H1 detector at a center-of-mass energy of 319 GeV. The fraction of inclusive neutral-current DIS events with an empty hemisphere is found to be $0.0112 \pm 3.9\,\%_\text{stat} \pm 4.5\,\%_\text{syst} \pm 1.6\,\%_\text{mod}$ in the selected kinematic region of $150< Q^2<1500$ GeV$^2$ and inelasticity $0.14< y<0.7$. The data sample corresponds to an integrated luminosity of 351.1 pb$^{-1}$, sufficient to enable differential cross section measurements of these events. The results show an enhanced discriminating power at lower Bjorken-$x$ among different Monte Carlo event generator predictions.

The H1 Collaboration reports the first measurement of the 1-jettiness event shape observable $\tau_1^b$ in neutral-current deep-inelastic electron-proton scattering (DIS). The observable $\tau_1^b$ is equivalent to a thrust observable defined in the Breit frame. The data sample was collected at the HERA $ep$ collider in the years 2003-2007 with center-of-mass energy of $\sqrt{s}=319\,\text{GeV}$, corresponding to an integrated luminosity of $351.1\,\text{pb}^{-1}$. Triple differential cross sections are provided as a function of $\tau_1^b$, event virtuality $Q^2$, and inelasticity $y$, in the kinematic region $Q^2>150\,\text{GeV}^{2}$. Single differential cross section are provided as a function of $\tau_1^b$ in a limited kinematic range. Double differential cross sections are measured, in contrast, integrated over $\tau_1^b$ and represent the inclusive neutral-current DIS cross section measured as a function of $Q^2$ and $y$. The data are compared to a variety of predictions and include classical and modern Monte Carlo event generators, predictions in fixed-order perturbative QCD where calculations up to $\mathcal{O}(\alpha_s^3)$ are available for $\tau_1^b$ or inclusive DIS, and resummed predictions at next-to-leading logarithmic accuracy matched to fixed order predictions at $\mathcal{O}(\alpha_s^2)$. These comparisons reveal sensitivity of the 1-jettiness observable to QCD parton shower and resummation effects, as well as the modeling of hadronization and fragmentation. Within their range of validity, the fixed-order predictions provide a good description of the data. Monte Carlo event generators are predictive over the full measured range and hence their underlying models and parameters can be constrained by comparing to the presented data.

The H1 Collaboration at HERA reports the first measurement of groomed event shape observables in deep inelastic electron-proton scattering (DIS) at $\sqrt{s}=319$ GeV, using data recorded between the years 2003 and 2007 with an integrated luminosity of $351$ pb$^{-1}$. Event shapes provide incisive probes of perturbative and non-perturbative QCD. Grooming techniques have been used for jet measurements in hadronic collisions; this paper presents the first application of grooming to DIS data. The analysis is carried out in the Breit frame, utilizing the novel Centauro jet clustering algorithm that is designed for DIS event topologies. Events are required to have squared momentum-transfer $Q^2 > 150$ GeV$^2$ and inelasticity $ 0.2 < y < 0.7$. We report measurements of the production cross section of groomed event 1-jettiness and groomed invariant mass for several choices of grooming parameter. Monte Carlo model calculations and analytic calculations based on Soft Collinear Effective Theory are compared to the measurements.

Abstract A brief summary of first tests of several monolithic frontend chips is presented. They are designed for readout of silicon strip detectors and have in common that they are all based on the same charge-sensitive preamplifier/shaper configuration, for which the main design goal was the lowest possible noise at low power consumption. Measurements show that low-noise levels of ENC = 165e − + 12e − /pF have been reached.

Abstract The Beam Condition Monitor (BCM) of the CMS detector at the LHC is a protection device similar to the LHC Beam Loss Monitor system. While the electronics used is the same, poly-crystalline Chemical Vapor Deposition (pCVD) diamonds are used instead of ionization chambers as the BCM sensor material. The main purpose of the system is the protection of the silicon Pixel and Strip tracking detectors by inducing a beam dump, if the beam losses are too high in the CMS detector. By comparing the detector current with the instantaneous luminosity, the BCM detector efficiency can be monitored. The number of radiation-induced defects in the diamond, reduces the charge collection distance, and hence lowers the signal. The number of these induced defects can be simulated using the FLUKA Monte Carlo simulation. The cross-section for creating defects increases with decreasing energies of the impinging particles. This explains, why diamond sensors mounted close to heavy calorimeters experience more radiation damage, because of the high number of low energy neutrons in these regions. The signal decrease was stronger than expected from the number of simulated defects. Here polarization from trapped charge carriers in the defects is a likely candidate for explaining the difference, as suggested by Transient Current Technique (TCT) measurements. A single-crystalline (sCVD) diamond sensor shows a faster relative signal decrease than a pCVD sensor mounted at the same location. This is expected, since the relative increase in the number of defects is larger in sCVD than in pCVD sensors.

Measurements of normalised cross sections for the production of photons and neutrons at very small angles with respect to the proton beam direction in deep-inelastic $$ep$$ scattering at HERA are presented as a function of the Feynman variable $$x_F$$ and of the centre-of-mass energy of the virtual photon-proton system $$W$$ . The data are taken with the H1 detector in the years 2006 and 2007 and correspond to an integrated luminosity of $$131~\text {pb}^{-1}$$ . The measurement is restricted to photons and neutrons in the pseudorapidity range $$\eta >7.9$$ and covers the range of negative four momentum transfer squared at the positron vertex $$6<Q^2<100$$ GeV $$^2$$ , of inelasticity $$0.05<y<0.6$$ and of $$70<W<245~$$ GeV. To test the Feynman scaling hypothesis the $$W$$ dependence of the $$x_F$$ dependent cross sections is investigated. Predictions of deep-inelastic scattering models and of models for hadronic interactions of high energy cosmic rays are compared to the measured cross sections.

Detector-plane prototypes of the very forward calorimetry of a future detector at an e+e− collider have been built and their performance was measured in an electron beam. The detector plane comprises silicon or GaAs pad sensors, dedicated front-end and ADC ASICs, and an FPGA for data concentration. Measurements of the signal-to-noise ratio and the response as a function of the position of the sensor are presented. A deconvolution method is successfully applied, and a comparison of the measured shower shape as a function of the absorber depth with a Monte-Carlo simulation is given.

Abstract Exclusive photoproduction of $${{\rho ^0}} (770)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mi>ρ</mml:mi> <mml:mn>0</mml:mn> </mml:msup> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>770</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> </mml:mrow> </mml:math> mesons is studied using the H1 detector at the ep collider HERA. A sample of about 900,000 events is used to measure single- and double-differential cross sections for the reaction $$\gamma p \rightarrow \pi ^{+}\pi ^{-}Y$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>γ</mml:mi> <mml:mi>p</mml:mi> <mml:mo>→</mml:mo> <mml:msup> <mml:mi>π</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:msup> <mml:mi>π</mml:mi> <mml:mo>-</mml:mo> </mml:msup> <mml:mi>Y</mml:mi> </mml:mrow> </mml:math> . Reactions where the proton stays intact ( $${{{m_Y}} {=}m_p}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>Y</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>p</mml:mi> </mml:msub> </mml:mrow> </mml:math> ) are statistically separated from those where the proton dissociates to a low-mass hadronic system ( $$m_p{&lt;}{{m_Y}} {&lt;}10~{{\text {GeV}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>p</mml:mi> </mml:msub> <mml:mo>&lt;</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>Y</mml:mi> </mml:msub> <mml:mo>&lt;</mml:mo> <mml:mn>10</mml:mn> <mml:mspace /> <mml:mtext>GeV</mml:mtext> </mml:mrow> </mml:math> ). The double-differential cross sections are measured as a function of the invariant mass $$m_{\pi \pi }$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>m</mml:mi> <mml:mrow> <mml:mi>π</mml:mi> <mml:mi>π</mml:mi> </mml:mrow> </mml:msub> </mml:math> of the decay pions and the squared 4-momentum transfer t at the proton vertex. The measurements are presented in various bins of the photon–proton collision energy $${{W_{\gamma p}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>W</mml:mi> <mml:mrow> <mml:mi>γ</mml:mi> <mml:mi>p</mml:mi> </mml:mrow> </mml:msub> </mml:math> . The phase space restrictions are $$0.5\le m_{\pi \pi } \le 2.2~{{\text {GeV}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>0.5</mml:mn> <mml:mo>≤</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mrow> <mml:mi>π</mml:mi> <mml:mi>π</mml:mi> </mml:mrow> </mml:msub> <mml:mo>≤</mml:mo> <mml:mn>2.2</mml:mn> <mml:mspace /> <mml:mtext>GeV</mml:mtext> </mml:mrow> </mml:math> , $$\vert t\vert \le 1.5~{{\text {GeV}^2}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mrow> <mml:mo>|</mml:mo> <mml:mi>t</mml:mi> <mml:mo>|</mml:mo> </mml:mrow> <mml:mo>≤</mml:mo> <mml:mn>1.5</mml:mn> <mml:mspace /> <mml:msup> <mml:mtext>GeV</mml:mtext> <mml:mn>2</mml:mn> </mml:msup> </mml:mrow> </mml:math> , and $$20 \le W_{\gamma p} \le 80~{{\text {GeV}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>20</mml:mn> <mml:mo>≤</mml:mo> <mml:msub> <mml:mi>W</mml:mi> <mml:mrow> <mml:mi>γ</mml:mi> <mml:mi>p</mml:mi> </mml:mrow> </mml:msub> <mml:mo>≤</mml:mo> <mml:mn>80</mml:mn> <mml:mspace /> <mml:mtext>GeV</mml:mtext> </mml:mrow> </mml:math> . Cross section measurements are presented for both elastic and proton-dissociative scattering. The observed cross section dependencies are described by analytic functions. Parametrising the $${m_{\pi \pi }}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>m</mml:mi> <mml:mrow> <mml:mi>π</mml:mi> <mml:mi>π</mml:mi> </mml:mrow> </mml:msub> </mml:math> dependence with resonant and non-resonant contributions added at the amplitude level leads to a measurement of the $${{\rho ^0}} (770)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mi>ρ</mml:mi> <mml:mn>0</mml:mn> </mml:msup> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>770</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> </mml:mrow> </mml:math> meson mass and width at $$m_\rho = 770.8{}^{+2.6}_{-2.7}~({\text {tot.}})~{{\text {MeV}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>ρ</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>770.8</mml:mn> <mml:msubsup> <mml:mrow /> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>2.7</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>2.6</mml:mn> </mml:mrow> </mml:msubsup> <mml:mspace /> <mml:mrow> <mml:mo>(</mml:mo> <mml:mtext>tot.</mml:mtext> <mml:mo>)</mml:mo> </mml:mrow> <mml:mspace /> <mml:mtext>MeV</mml:mtext> </mml:mrow> </mml:math> and $$\Gamma _\rho = 151.3 {}^{+2.7}_{-3.6}~({\text {tot.}})~{{\text {MeV}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>Γ</mml:mi> <mml:mi>ρ</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>151.3</mml:mn> <mml:msubsup> <mml:mrow /> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>3.6</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>2.7</mml:mn> </mml:mrow> </mml:msubsup> <mml:mspace /> <mml:mrow> <mml:mo>(</mml:mo> <mml:mtext>tot.</mml:mtext> <mml:mo>)</mml:mo> </mml:mrow> <mml:mspace /> <mml:mtext>MeV</mml:mtext> </mml:mrow> </mml:math> , respectively. The model is used to extract the $${{\rho ^0}} (770)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mi>ρ</mml:mi> <mml:mn>0</mml:mn> </mml:msup> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>770</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> </mml:mrow> </mml:math> contribution to the $$\pi ^{+}\pi ^{-}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mi>π</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:msup> <mml:mi>π</mml:mi> <mml:mo>-</mml:mo> </mml:msup> </mml:mrow> </mml:math> cross sections and measure it as a function of t and $${W_{\gamma p}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>W</mml:mi> <mml:mrow> <mml:mi>γ</mml:mi> <mml:mi>p</mml:mi> </mml:mrow> </mml:msub> </mml:math> . In a Regge asymptotic limit in which one Regge trajectory $$\alpha (t)$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>α</mml:mi> <mml:mo>(</mml:mo> <mml:mi>t</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> dominates, the intercept $$\alpha (t{=}0) = 1.0654\ {}^{+0.0098}_{-0.0067}~({\text {tot.}})$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>α</mml:mi> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>t</mml:mi> <mml:mo>=</mml:mo> <mml:mn>0</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> <mml:mo>=</mml:mo> <mml:mn>1.0654</mml:mn> <mml:mspace /> <mml:msubsup> <mml:mrow /> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>0.0067</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.0098</mml:mn> </mml:mrow> </mml:msubsup> <mml:mspace /> <mml:mrow> <mml:mo>(</mml:mo> <mml:mtext>tot.</mml:mtext> <mml:mo>)</mml:mo> </mml:mrow> </mml:mrow> </mml:math> and the slope $$\alpha ^\prime (t{=}0) = 0.233 {}^{+0.067 }_{-0.074 }~({\text {tot.}}) ~{{\text {GeV}^{-2}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mi>α</mml:mi> <mml:mo>′</mml:mo> </mml:msup> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>t</mml:mi> <mml:mo>=</mml:mo> <mml:mn>0</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> <mml:mo>=</mml:mo> <mml:mn>0.233</mml:mn> <mml:msubsup> <mml:mrow /> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>0.074</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.067</mml:mn> </mml:mrow> </mml:msubsup> <mml:mspace /> <mml:mrow> <mml:mo>(</mml:mo> <mml:mtext>tot.</mml:mtext> <mml:mo>)</mml:mo> </mml:mrow> <mml:mspace /> <mml:msup> <mml:mtext>GeV</mml:mtext> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> of the t dependence are extracted for the case $$m_Y{=}m_p$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>Y</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>p</mml:mi> </mml:msub> </mml:mrow> </mml:math> .

Polycrystalline artificial diamond produced by chemical vapor deposition (pCVD) is a possible sensor material for the beam calorimeter of the ILC. The requirements are linearity over a large range of flux and radiation hardness against a total ionizing dose of several MGy per year of operation. A hadron test beam at the CERN PS was used to study the linearity of the response of pCVD sensors. An electron test beam at the S-DALINAC was used to measure the charge collection distance (CCD) as a function of the absorbed dose up to several MGy. Current-voltage characteristics of these sensors were measured before and after the irradiation as well as the dependence of the CCD on the applied electric field before and after the irradiation.

The cross section for $ep \rightarrow e\, b\bar{b} X$ in photoproduction is measured with the H1 detector at the ep-collider HERA. The decay channel $b\bar{b} \rightarrow ee X'$ is selected by identifying the semi-electronic decays of the b-quarks. The total production cross section is measured in the kinematic range given by the photon virtuality Q 2≤1 GeV2, the inelasticity 0.05≤y≤0.65 and the pseudorapidity of the b-quarks $|\eta(b)|, |\eta(\bar{b})|\leq2$ . The differential production cross section is measured as a function of the average transverse momentum of the beauty quarks 〈P T (b)〉 down to the threshold. The results are compared to next-to-leading-order QCD predictions.

A bstract A search for new top quark interactions is performed within the framework of an effective field theory using the associated production of either one or two top quarks with a Z boson in multilepton final states. The data sample corresponds to an integrated luminosity of 138 fb − 1 of proton-proton collisions at $$ \sqrt{s} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> </mml:math> = 13 TeV collected by the CMS experiment at the LHC. Five dimension-six operators modifying the electroweak interactions of the top quark are considered. Novel machine-learning techniques are used to enhance the sensitivity to effects arising from these operators. Distributions used for the signal extraction are parameterized in terms of Wilson coefficients describing the interaction strengths of the operators. All five Wilson coefficients are simultaneously fit to data and 95% confidence level intervals are computed. All results are consistent with the SM expectations.

Abstract We report spectral and imaging performance of a pixelated CdZnTe detector custom designed for the MeVCube project: a small Compton telescope on a CubeSat platform. MeVCube is expected to cover the energy range between 200 keV and 4 MeV, with a sensitivity comparable to the one of the last generation of larger satellites. In order to achieve this goal, an energy resolution of few percent in full width at half maximum (FWHM) and a 3-D spatial resolution of few millimeters for the individual detectors are needed. The severe power constraints present in small satellites require very low power read-out electronics for the detector. Our read-out is based on the VATA450.3 ASIC developed by Ideas , with a power consumption of only 0.25 mW/channel, which exhibits good performance in terms of dynamic range, noise and linearity. A 2.0 cm× 2.0 cm× 1.5 cm CdZnTe detector, with a custom 8 × 8 pixel anode structure read-out by a VATA450.3 ASIC, has been tested. A preliminary read-out system for the cathode, based on a discrete Amptek A250F charge sensitive pre-amplifier and a DRS4 ASIC, has been implemented. An energy resolution around 3% FWHM has been measured at a gamma energy of 662 keV; at 200 keV the average energy resolution is 6.5%, decreasing to ≲ 2% at energies above 1 MeV. A 3-D spatial resolution of ≈ 2 mm is achieved in each dimension.

A search for second and third generation scalar and vector leptoquarks produced in ep collisions via the lepton flavour violating processes ep→μX and ep→τX is performed by the H1 experiment at HERA. The full data sample taken at a centre-of-mass energy s=319GeV is used for the analysis, corresponding to an integrated luminosity of 245 pb−1 of e+p and 166 pb−1 of e−p collision data. No evidence for the production of such leptoquarks is observed in the H1 data. Leptoquarks produced in e±p collisions with a coupling strength of λ=0.3 and decaying with the same coupling strength to a muon–quark pair or a tau–quark pair are excluded at 95% confidence level up to leptoquark masses of 712 GeV and 479 GeV, respectively.

A prototype of a luminometer, designed for a future $$e^+e^-$$ collider detector, and consisting at present of a four-plane module, was tested in the CERN PS accelerator T9 beam. The objective of this beam test was to demonstrate a multi-plane tungsten/silicon operation, to study the development of the electromagnetic shower and to compare it with MC simulations. The Molière radius has been determined to be 24.0 ± 0.6 (stat.) ± 1.5 (syst.) mm using a parametrization of the shower shape. Very good agreement was found between data and a detailed Geant4 simulation.

First measurements are presented of the diffractive cross section σ ep→eXY at centre-of-mass energies $\sqrt{s}$ of 225 and $252\mathrm {\;GeV}$ , together with a precise new measurement at $\sqrt{s}$ of $319\mathrm {\;GeV}$ , using data taken with the H1 detector in the years 2006 and 2007. Together with previous H1 data at $\sqrt{s}$ of $301\mathrm {\;GeV}$ , the measurements are used to extract the diffractive longitudinal structure function $F_{L}^{D}$ in the range of photon virtualities $4.0 \leq Q^{2} \leq 44.0\mathrm {\;GeV}^{2}$ and fractional proton longitudinal momentum loss 5×10−4≤x ℙ≤3×10−3. The measured $F_{L}^{D}$ is compared with leading twist predictions based on diffractive parton densities extracted in NLO QCD fits to previous measurements of diffractive Deep-Inelastic Scattering and with a model which additionally includes a higher twist contribution derived from a colour dipole approach. The ratio of the diffractive cross section induced by longitudinally polarised photons to that for transversely polarised photons is extracted and compared with the analogous quantity for inclusive Deep-Inelastic Scattering.

Deep-inelastic positron-proton scattering events at low photon virtuality, Q 2, with a forward jet, produced at small angles with respect to the proton beam, are measured with the H1 detector at HERA. A subsample of events with an additional jet in the central region is also studied. For both samples, differential cross sections and normalised distributions are measured as a function of the azimuthal angle difference, Δϕ, between the forward jet and the scattered positron in bins of the rapidity distance, Y, between them. The data are compared to predictions of Monte Carlo generators based on different evolution approaches as well as to next-to-leading order calculations in order to test the sensitivity to QCD evolution mechanisms.

The inclusive photoproduction of D\ast mesons and of D\ast-tagged dijets is investigated with the H1 detector at the ep collider HERA. The kinematic region covers small photon virtualities Q2 < 2 GeV2 and photon-proton centre-of-mass energies of 100 < Wgp < 285 GeV. Inclusive D\ast meson differential cross sections are measured for central rapidities |eta(D\ast)| < 1.5 and transverse momenta pT (D\ast) > 1.8 GeV. The heavy quark production process is further investigated in events with at least two jets with transverse momentum pT (jet) > 3.5 GeV each, one containing the D\ast meson. Differential cross sections for D\ast-tagged dijet production and for correlations between the jets are measured in the range |eta(D\ast)| < 1.5 and pT (D\ast) > 2.1 GeV. The results are compared with predictions from Monte Carlo simulations and next-to-leading order perturbative QCD calculations.

A new design of a detector plane of sub-millimetre thickness for an electromagnetic sampling calorimeter is presented. It is intended to be used in the luminometers LumiCal and BeamCal in future linear e $$^{+}$$ e $$^{-}$$ collider experiments. The detector planes were produced utilising novel connectivity scheme technologies. They were installed in a compact prototype of the calorimeter and tested at DESY with an electron beam of energy 1–5 GeV. The performance of a prototype of a compact LumiCal comprising eight detector planes was studied. The effective Molière radius at 5 GeV was determined to be (8.1 ± 0.1 (stat) ± 0.3 (syst)) mm, a value well reproduced by the Monte Carlo (MC) simulation (8.4 ± 0.1) mm. The dependence of the effective Molière radius on the electron energy in the range 1–5 GeV was also studied. Good agreement was obtained between data and MC simulation.

The Pixel Luminosity Telescope is a silicon pixel detector dedicated to luminosity measurement at the CMS experiment at the LHC. It is located approximately 1.75 m from the interaction point and arranged into 16 "telescopes", with eight telescopes installed around the beam pipe at either end of the detector and each telescope composed of three individual silicon sensor planes. The per-bunch instantaneous luminosity is measured by counting events where all three planes in the telescope register a hit, using a special readout at the full LHC bunch-crossing rate of 40 MHz. The full pixel information is read out at a lower rate and can be used to determine calibrations, corrections, and systematic uncertainties for the online and offline measurements. This paper details the commissioning, operational history, and performance of the detector during Run 2 (2015-18) of the LHC, as well as preparations for Run 3, which will begin in 2022.

The development and first results are described of a silicon strip detector telescope for the HERA experiment H1 designed to measure the polar angle of deep inelastic scattered electrons at small Bjorken x and low momentum transfers Q2.

The production of photons at very small angles with respect to the proton beam direction is studied in deep-inelastic positron-proton scattering at HERA. The data are taken with the H1 detector in the years 2006 and 2007 and correspond to an integrated luminosity of $126 \mathrm{pb}^{-1}$. The analysis covers the range of negative four momentum transfer squared at the positron vertex $6<Q^2<100$ GeV$^2$ and inelasticity $0.05<y<0.6$. Cross sections are measured for the most energetic photon with pseudorapidity $\eta>7.9$ as a function of its transverse momentum $p_T^{lead}$ and longitudinal momentum fraction of the incoming proton $x_L^{lead}$. In addition, the cross sections are studied as a function of the sum of the longitudinal momentum fraction $x_L^{sum}$ of all photons in the pseudorapidity range $\eta>7.9$. The cross sections are normalised to the inclusive deep-inelastic scattering cross section and compared to the predictions of models of deep-inelastic scattering and models of the hadronic interactions of high energy cosmic rays.

The parameters of the electroweak theory are determined in a combined electroweak and QCD analysis using all deep-inelastic $$e^+p$$ and $$e^-p$$ neutral current and charged current scattering cross sections published by the H1 Collaboration, including data with longitudinally polarised lepton beams. Various fits to Standard Model parameters in the on-shell scheme are performed. The mass of the W boson is determined as $$m_W=80.520\pm 0.115~\mathrm {GeV} $$ . The axial-vector and vector couplings of the light quarks to the Z boson are also determined. Both results improve the precision of previous H1 determinations based on HERA-I data by about a factor of two. Possible scale dependence of the weak coupling parameters in both neutral and charged current interactions beyond the Standard Model is also studied. All results are found to be consistent with the Standard Model expectations.

Signals of QCD instanton-induced processes are searched for in neutral current deep-inelastic scattering at the electron-proton collider HERA in the kinematic region defined by the Bjorken-scaling variable $$x > 10^{-3}$$ , the inelasticity $$0.2< y < 0.7$$ and the photon virtuality $$150< Q^2 < 15000$$ GeV $$^2$$ . The search is performed using H1 data corresponding to an integrated luminosity of 351 pb $$^{-1}$$ . No evidence for the production of QCD instanton-induced events is observed. Upper limits on the cross section for instanton-induced processes between 1.5 and 6 pb, at $$95\,\,\%$$ confidence level, are obtained depending on the kinematic domain in which instantons could be produced. Compared to earlier publications, the limits are improved by an order of magnitude and for the first time are challenging predictions.

The strong coupling constant $\alpha_s(M_Z)$ is determined from inclusive jet and dijet cross sections in neutral-current deep-inelastic $ep$ scattering (DIS) measured at HERA by the H1 collaboration using next-to-next-to-leading order (NNLO) QCD predictions. The dependence of the NNLO predictions and of the resulting value of $\alpha_s(M_Z)$ at the $Z$-boson mass $m_Z$ are studied as a function of the choice of the renormalisation and factorisation scales. Using inclusive jet and dijet data together, the strong coupling constant is determined to be $\alpha_s(M_Z)=0.1166\,(19)_{\rm exp}\,(24)_{\rm th}$. Complementary, $\alpha_s(M_Z)$ is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value $\alpha_s(M_Z)=0.1147\,(25)_{\rm tot}$ obtained is consistent with the determination from jet data alone. The impact of the jet data on the PDFs is studied. The running of the strong coupling is tested at different values of the renormalisation scale and the results are found to be in agreement with expectations.

Measurements of cross sections for beauty and charm events with dijets and a muon in the photoproduction regime at HERA are presented. The data were collected with the H1 detector and correspond to an integrated luminosity of 179 pb−1. Events with dijets of transverse momentum $P_{T}^{\mathrm{jet}1}> 7\ \mbox{GeV}$ and $P_{T}^{\mathrm{jet}2}> 6\ \mbox{GeV}$ in the pseudorapidity range −1.5<η jet<2.5 in the laboratory frame are selected in the kinematic region of photon virtuality Q 2<2.5 GeV2 and inelasticity 0.2<y<0.8. One of the two selected jets must be associated to a muon with $P_{T}^{\mu} > 2.5\ \mbox{GeV}$ in the pseudorapidity range −1.3<η μ <1.5. The fractions of beauty and charm events are determined using the impact parameters of the muon tracks with respect to the primary vertex and their transverse momentum relative to the axis of the associated jet. Both variables are reconstructed using the H1 vertex detector. The measurements are in agreement with QCD predictions at leading and next-to-leading order.

The L3 central tracking detector has been in operation since the start-up of LEP (Large Electron Positron collider) in 1989. This detector consists of a Time Expansion Chamber (TEC), a layer of Plastic Scintillating Fibers and a Z-chamber. The TEC gives a high spatial resolution and an excellent multi-track reconstruction capability. The fibers are designed to calibrate the drift velocity with high precision. The Z-Chamber provides TEC with accurate information about the z-coordinates of the tracks. A description of the design and the infrastructure of these three detectors, including the readout and data acquisition system, is given. The performance of the detectors during the 1990 and 1991 LEP running periods is presented.

The CMS beam and radiation monitoring subsystem BCM1F (Fast Beam Condition Monitor) consists of 8 individual diamond sensors situated around the beam pipe within the pixel detector volume, for the purpose of fast bunch-by-bunch monitoring of beam background and collision products. In addition, effort is ongoing to use BCM1F as an online luminosity monitor. BCM1F will be running whenever there is beam in LHC, and its data acquisition is independent from the data acquisition of the CMS detector, hence it delivers luminosity even when CMS is not taking data. A report is given on the performance of BCM1F during LHC run I, including results of the van der Meer scan and on-line luminosity monitoring done in 2012. In order to match the requirements due to higher luminosity and 25 ns bunch spacing, several changes to the system must be implemented during the upcoming shutdown, including upgraded electronics and precise gain monitoring. First results from Run II preparation are shown.

The authors present measurements under hydrostatic pressure on Si delta-doped GaAs. From the measurements they conclude that the energy position of the DX level is shifted away from the Gamma conduction band minimum at high doping concentrations. This shift is consistent with measurements carried out on bulk GaAs heavily doped with silicon.

The CMS Beam Conditions and Radiation Monitoring System (BRM) [1] is composed of different subsystems that perform monitoring of, as well as providing the CMS detector protection from, adverse beam conditions inside and around the CMS experiment. This paper presents the Fast Beam Conditions Monitoring subsystem (BCM1F), which is designed for fast flux monitoring based on bunch by bunch measurements of both beam halo and collision product contributions from the LHC beam. The BCM1F is located inside the CMS pixel detector volume close to the beam-pipe and provides real-time information. The detector uses sCVD (single-crystal Chemical Vapor Deposition) diamond sensors and radiation hard front-end electronics, along with an analog optical readout of the signals.

Extremely radiation hard sensors are needed in particle physics experiments to instrument the region near the beam pipe. Examples are beam halo and beam loss monitors at the Large Hadron Collider, FLASH or XFEL. Currently artificial diamond sensors are widely used. In this paper single crystal sapphire sensors are considered as a promising alternative. Industrially grown sapphire wafers are available in large sizes, are of low cost and, like diamond sensors, can be operated without cooling. Here we present results of an irradiation study done with sapphire sensors in a high intensity low energy electron beam. Then, a multichannel direction-sensitive sapphire detector stack is described. It comprises 8 sapphire plates of 1 cm2 size and 525 μ m thickness, metallized on both sides, and apposed to form a stack. Each second metal layer is supplied with a bias voltage, and the layers in between are connected to charge-sensitive preamplifiers. The performance of the detector was studied in a 5 GeV electron beam. The charge collection efficiency measured as a function of the bias voltage rises with the voltage, reaching about 10% at 095 V. The signal size obtained from electrons crossing the stack at this voltage is about 02200 e, where e is the unit charge.

The MAJC 5200 is a dual 32b microprocessor system-on-a-chip, utilizing 0.22 /spl mu/m CMOS with all-Cu interconnect. Two CPUs, delivering GGFLOPS and 13GOPS at 500 MHz, are tightly coupled through a shared, coherent, 4-way set associative 16 KB data cache, and an on-chip 4 GB/s switch. Each CPU is a 4-issue VLIW engine.

F. D. Aaron5,h, C. Alexa5, V. Andreev25, S. Backovic30, A. Baghdasaryan38, S. Baghdasaryan38, E. Barrelet29, W. Bartel11, K. Begzsuren35, A. Belousov25, P. Belov11, J. C. Bizot27, V. Boudry28, I. Bozovic-Jelisavcic2, J. Bracinik3, G. Brandt11, M. Brinkmann11, V. Brisson27, D. Britzger11, D. Bruncko16, A. Bunyatyan13,38, A. Bylinkin24, L. Bystritskaya24, A. J. Campbell11, K. B. Cantun Avila22, F. Ceccopieri4, K. Cerny32, V. Cerny16,g, V. Chekelian26, J. G. Contreras22, J. A. Coughlan6, J. Cvach31, J. B. Dainton18, K. Daum37,a,c, B. Delcourt27, J. Delvax4, E. A. De Wolf4, C. Diaconu21, M. Dobre12,j,k, V. Dodonov13, A. Dossanov12,26, A. Dubak30,f, G. Eckerlin11, S. Egli36, A. Eliseev25, E. Elsen11, L. Favart4, A. Fedotov24, R. Felst11, J. Feltesse10, J. Ferencei16, D.-J. Fischer11, M. Fleischer11, A. Fomenko25, E. Gabathuler18, J. Gayler11, S. Ghazaryan11, A. Glazov11, L. Goerlich7, N. Gogitidze25, M. Gouzevitch11,d, C. Grab40, A. Grebenyuk11, T. Greenshaw18, G. Grindhammer26, S. Habib11, D. Haidt11, R. C. W. Henderson17, E. Hennekemper15, H. Henschel39, M. Herbst15, G. Herrera23, M. Hildebrandt36, K. H. Hiller39, D. Hoffmann21, R. Horisberger36, T. Hreus4, F. Huber14, M. Jacquet27, X. Janssen4, L. Jonsson20, H. Jung11,4, M. Kapichine9, I. R. Kenyon3, C. Kiesling26, M. Klein18, C. Kleinwort11, T. Kluge18, R. Kogler12, P. Kostka39, M. Kramer11, J. Kretzschmar18, K. Kruger15, M. P. J. Landon19, W. Lange39, G. Lastovicka-Medin30, P. Laycock18, A. Lebedev25, V. Lendermann15, S. Levonian11, K. Lipka11,j, B. List11, J. List11, B. Lobodzinski11, R. Lopez-Fernandez23, V. Lubimov24, E. Malinovski25, H.-U. Martyn1, S. J. Maxfield18, A. Mehta18, A. B. Meyer11, H. Meyer37, J. Meyer11, S. Mikocki7, I. Milcewicz-Mika7, F. Moreau28, A. Morozov9, J. V. Morris6, K. Muller41, Th. Naumann39, P. R. Newman3, C. Niebuhr11, D. Nikitin9, G. Nowak7, K. Nowak12, J. E. Olsson11, D. Ozerov11, P. Pahl11, V. Palichik9, I. Panagoulias11,b,y, M. Pandurovic2, Th. Papadopoulou11,b,y, C. Pascaud27, G. D. Patel18, E. Perez10,e, A. Petrukhin11, I. Picuric30, H. Pirumov14, D. Pitzl11, R. Placakytė11, B. Pokorny32, R. Polifka32,l, B. Povh13, V. Radescu11, N. Raicevic30, T. Ravdandorj35, P. Reimer31, E. Rizvi19, P. Robmann41, R. Roosen4, A. Rostovtsev24, M. Rotaru5, J. E. Ruiz Tabasco22, S. Rusakov25, D. Salek32, D. P. C. Sankey6, M. Sauter14, E. Sauvan21,m, S. Schmitt11, L. Schoeffel10, A. Schoning14, H.-C. Schultz-Coulon15, F. Sefkow11, L. N. Shtarkov25, S. Shushkevich11, T. Sloan17, Y. Soloviev11,25, P. Sopicki7, D. South11, V. Spaskov9, A. Specka28, Z. Staykova4, M. Steder11, B. Stella33, G. Stoicea5, U. Straumann41, T. Sykora4,32, P. D. Thompson3, T. H. Tran27, D. Traynor19, P. Truol41, I. Tsakov34, B. Tseepeldorj35,i, J. Turnau7, A. Valkarova32, C. Vallee21, P. Van Mechelen4, Y. Vazdik25, D. Wegener8, E. Wunsch11, J. Žacek32, J. Zalesak31, Z. Zhang27, A. Zhokin24, R. Žlebcik32, H. Zohrabyan38, F. Zomer27

The Beam Radiation Instrumentation and Luminosity Project of the CMS experiment consists of several beam monitoring systems and luminometers. The upgraded Fast Beam Conditions Monitor is based on 24 single crystal diamond sensors with a two-pad metallization and a custom designed readout. Signals for real time monitoring are transmitted to the counting room, where they are received and processed by new back-end electronics designed to measure count rates on LHC collision, beam induced background and activation products to be used to determine the luminosity and the machine induced background. The system architecture and the signal processing algorithms will be presented.

The CMS Beam Radiation Instrumentation and Luminosity (BRIL) project is composed of several systems providing the experiment protection from adverse beam conditions while also measuring the online luminosity and beam background. Although the readout bandwidth of the Fast Beam Conditions Monitoring system (BCM1F—one of the faster monitoring systems of the CMS BRIL), was sufficient for the initial LHC conditions, the foreseen enhancement of the beams parameters after the LHC Long Shutdown-1 (LS1) imposed the upgrade of the system. This paper presents the new BCM1F, which is designed to provide real-time fast diagnosis of beam conditions and instantaneous luminosity with readout able to resolve the 25 ns bunch structure.

The authors have determined the effective electron mass in a GaAs/Al0.33Ga0.67As heterostructure from the temperature dependence of the amplitude of the Shubnikov-de Haas oscillations. The effective mass is expected to increase with increasing electron concentration due to the non-parabolicity of the conduction band. The effective mass will also increase when the authors apply a hydrostatic pressure. They evaluated the effective mass in their sample at different electron concentrations and different hydrostatic pressures and have shown that the experimental values fit very well with the theoretically predicted values.

The Compact Muon Solenoid (CMS) is one of the two large, general purpose experiments situated at the LHC at CERN. As with all high energy physics experiments, knowledge of the beam conditions and luminosity is of vital importance. The Beam Conditions and Radiation Monitoring System (BRM) is installed in CMS to protect the detector and to provide feedback to LHC on beam conditions. It is composed of several sub-systems that measure the radiation level close to or inside all sub-detectors, monitor the beam halo conditions with different time resolution, support beam tuning and protect CMS in case of adverse beam conditions by firing a beam abort signal. This paper presents three of the BRM subsystems: the Fast Beam Conditions Monitor (BCM1F), which is designed for fast flux monitoring, measuring with nanosecond time resolution, both the beam halo and collision products; the Beam Scintillator Counters (BSC), that provide hit rates and time information of beam halo and collision products; and the Beam Conditions Monitors (BCM) used as a protection system that can trigger a beam dump when beam losses occur in order to prevent damage to the pixel and tracker detectors. A description of the systems and a characterization on the basis of data collected during LHC operation is presented.

The Beam Conditions and Radiation Monitoring System (BRM), is installed in CMS to protect the CMS detector from high beam losses and to provide feedback to the LHC and CMS on the beam conditions. The primary detector subsystems are based on either single crystal diamond sensors (BCM1F) for particle counting with nanosecond resolution or on polycrystalline diamonds (BCM2; BCM1L) for integrated signal current measurements. Beam scintillation counters (BSC) are also used during low luminosity running. The detectors have radiation hard front-end electronics and are read out independently of the CMS central data acquisition and are online whenever there is beam in the LHC machine. The various sub-systems exploit different time resolutions and position locations to be able to monitor the beam induced backgrounds and the flux of particles produced during collisions. This paper describes the CMS BRM system and the complementary aspects of the installed BRM sub-detectors to measure both single particle count rates and signal currents originating from beam backgrounds and collision products in CMS.

The CMS beam and radiation monitoring subsystem BCM1F during LHC Run I consisted of 8 individual diamond sensors situated around the beam pipe within the tracker detector volume, for the purpose of fast monitoring of beam background and collision products. Effort is ongoing to develop the use of BCM1F as an online bunch-by-bunch luminosity monitor. BCM1F will be running whenever there is beam in LHC, and its data acquisition is independent from the data acquisition of the CMS detector, hence it delivers luminosity even when CMS is not taking data. To prepare for the expected increase in the LHC luminosity and the change from 50 ns to 25 ns bunch separation, several changes to the system are required, including a higher number of sensors and upgraded electronics. In particular, a new real-time digitizer with large memory was developed and is being integrated into a multi-subsystem framework for luminosity measurement. Current results from Run II preparation will be shown, including results from the January 2014 test beam. Presented at TIPP2014 3rd International Conference on Technology and Instrumentation in Particle Physics, Upgraded Fast Beam Conditions Monitor for CMS online luminosity measurement Jessica Lynn Leonard*, Maria Hempel†, Hans Henschel, Olena Karacheban, Wolfgang Lange, Wolfgang Lohmann†, Roberval Walsh DESY Zeuthen, Germany E-mail:jessica.lynn.leonard@desy.de, maria.hempel@desy.de, hans.henschel@desy.de, olena.karacheban@desy.de, wolfgang.lange@desy.de, wolfgang.lohmann@desy.de, roberval.walsh@desy.de Anne Dabrowski, Vladimir Ryjov CERN Geneva, Switzerland E-mail: anne.evelyn.dabrowski@cern.ch, vladimir.ryjov@cern.ch David Stickland Princeton University Princeton, New Jersey, USA E-mail: david.peter.stickland@cern.ch The CMS beam and radiation monitoring subsystem BCM1F during LHC Run I consisted of 8 individual diamond sensors situated around the beam pipe within the tracker detector volume, for the purpose of fast monitoring of beam background and collision products. Effort is ongoing to develop the use of BCM1F as an online bunch-by-bunch luminosity monitor. BCM1F will be running whenever there is beam in LHC, and its data acquisition is independent from the data acquisition of the CMS detector, hence it delivers luminosity even when CMS is not taking data. To prepare for the expected increase in the LHC luminosity and the change from 50 ns to 25 ns bunch separation, several changes to the system are required, including a higher number of sensors and upgraded electronics. In particular, a new real-time digitizer with large memory was developed and is being integrated into a multi-subsystem framework for luminosity measurement. Current results from Run II preparation will be discussed, including results from the January 2014 test beam. Technology and Instrumentation in Particle Physics 2014 2-6 June, 2014 Amsterdam, the Netherlands * Speaker † Also at Brandenburg Technical University, Cottbus, Germany  Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. http://pos.sissa.it BCM1F for CMS online luminosity Jessica Lynn Leonard 1. Overview of BCM1F The CMS Fast Beam Condition Monitor (BCM1F)[1] provides bunch-by-bunch information on the flux of beam halo and collision products passing through the inner CMS detector[2]. The system was originally designed to monitor the condition of the beam to ensure low enough tracker occupancy for data-taking. However, BCM1F's purpose has evolved to include fast measurement of luminosity in order to function as an online luminometer.

Over the past year the RD42 collaboration continued to improve CVD diamond detectors for high luminosity experiments at the LHC. We have made extensive progress on diamond quality and radiation hardness studies using the highest quality diamond were performed up to fluences of 20 ◊ 10 15 p/cm 2 . Transforming this technology to specific requirements of the LHC has begun. The first ATLAS diamond pixel module was constructed using the same bump-bonding and electronics that the present ATLAS pixel modules use. Both ATLAS and CMS have tested and are planning to use diamond for their beam conditions monitoring systems. In this report we present the progress made and the requirements specific to the programme.

A recoil detector will be installed surrounding the internal gas target of the HERMES experiment at DESY. The recoil detector will improve the selection of exclusive events by a direct measurement of the momentum and track direction of the recoiling particle. The innermost layer of this recoil detector is a new silicon strip detector (SSD). Since Monte Carlo simulations predict proton momenta as low as 100 MeV/c, the SSD will be placed inside the HERA vacuum. A new setup of the electronics enables a dynamic range from below 4 fC at a signal-to-noise ratio of 6.8 up to 270 fC. In this paper, the assembly of the first module and the final setup within the HERMES experiment will be presented. Results from charge-injection tests of a prototype module are given.

Abstract A setup designed for the investigation of the properties of coherent scintillating fiber bundles and ribbons is described in some detail. The fiber readout is realized by a three stage image intensifier chain and a CCD matrix. A silicon strip detector telescope defines a precise reference system. The results of first measurements in a 5 GeV/ c hadron beam at the CERN proton synchrotron demonstrate the capabilities of the apparatus.

We have measured minority-carrier lifetimes of up to 4.9 μs in GaAs layers that have been grown by low-pressure organometallic vapor phase epitaxy. These lifetimes, representing a major improvement compared with previously obtained results, are governed by radiative recombination processes. Carbon incorporation during crystal growth at low arsine partial pressures is of prime importance in understanding the origin of these very long lifetimes.

Measurements of $$D^{*}(2010)$$ meson production in diffractive deep inelastic scattering $$(5<Q^{2}<100\,\mathrm{GeV}^{2})$$ are presented which are based on HERA data recorded at a centre-of-mass energy $$\sqrt{s} = 319\,\mathrm{GeV}$$ with an integrated luminosity of 287 pb $$^{-1}$$ . The reaction $$ep \rightarrow eXY$$ is studied, where the system X, containing at least one $$D^{*}(2010)$$ meson, is separated from a leading low-mass proton dissociative system Y by a large rapidity gap. The kinematics of $$D^{*}$$ candidates are reconstructed in the $$D^{*}\rightarrow K \pi \pi $$ decay channel. The measured cross sections compare favourably with next-to-leading order QCD predictions, where charm quarks are produced via boson-gluon fusion. The charm quarks are then independently fragmented to the $$D^{*}$$ mesons. The calculations rely on the collinear factorisation theorem and are based on diffractive parton densities previously obtained by H1 from fits to inclusive diffractive cross sections. The data are further used to determine the diffractive to inclusive $$D^{*}$$ production ratio in deep inelastic scattering.

We are describing a high speed VME readout and control module developed and presently working at the H1 experiment at DESY in Hamburg. It has the capability to read out 4 × 2048 analogue data channels at sampling rates up to 10 MHz with a dynamic input range of 1 V. The nominal resolution of the A/D converters can be adjusted between 8 and 12 bit. At the latter resolution we obtain signal-to-noise ratio better than 61.4 dB at a conversion rate of 5 MSps. At this data rate all 8192 detector channels can be read out to the internal raw data memory and VME interface within about 410 μs and 510 μs, respectively. The pedestal subtracted signals can be analyzed on-line. At a raw data hit occupation of 10%, the VME readout time is 50 μs per module. Each module provides four complementary CMOS signals to control the front-end electronics and four independent sets of power supplies for analogue and digital voltages (10 V, 100 mA) to drive the front-end electronics and for the bias voltage (100 V, 1.2 mA) to assure the full functionality of the detectors and the readout.

The Beam Radiation Instrumentation and Luminosity Project of the CMS experiment, consists of several beam monitoring systems. One system, the upgraded Fast Beams Condition Monitor, is based on 24 single crystal CVD diamonds with a double-pad sensor metallization and a custom designed readout. Signals for real-time monitoring are transmitted to the counting room, where they are received and processed by new back-end electronics designed to extract information on LHC collision, beam induced background and activation products. The Slow Control Driver is designed for the front-end electronics configuration and control. The system architecture and the upgrade status will be presented.

Das Fortleben des germanischen Heidentums nach der Christianisierung was published in Band 2 Literaturgeschichte. Heldensage und Heldendichtung. Religions- und Sittengeschichte. Recht und Gesellschaft on page 378.

The Fast Beam Conditions Monitor, BCM1F, in the Compact Muon Solenoid, CMS, experiment was operated since 2008 and delivered invaluable information on the machine induced background in the inner part of the CMS detector supporting a safe operation of the inner tracker and high quality data. Due to the shortening of the time between two bunch crossings from 50 ns to 25 ns and higher expected luminosity at the Large Hadron Collider, LHC, in 2015, BCM1F needed an upgrade to higher bandwidth. In addition, BCM1F is used as an on-line luminometer operated independently of CMS. To match these requirements, the number of single crystal diamond sensors was enhanced from 8 to 24. Each sensor is subdivided into two pads, leading to 48 readout channels. Dedicated fast front-end ASICs were developed in 130 nm technology, and the back-end electronics is completely upgraded. An assembled prototype BCM1F detector comprising sensors, a fast front-end ASIC and optical analog readout was studied in a 5 GeV electron beam at the DESY-II accelerator. Results on the performance are given.

We show that the inter-edge-channel scattering of a two-dimensional electron gas in the quantum Hall regime can be dramatically suppressed when the confining potential at the boundaries of the sample is altered. The confining potential is changed by making use of a half-gated GaAs/${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As heterostructure. In this configuration, the (spin-split) edge channels on the same side of the sample can be separated by a macroscopic (\ensuremath{\sim}1 mm) distance. We use an interior contact to detect or feed the innermost edge channels as opposed to quantum point contacts or contacts with cross gates which are coupled to the outermost edge channels. Due to the large spatial separation of the respective edge channels, it is shown that the inter-edge-channel scattering can be totally suppressed and therefore the equilibration length becomes arbitrarily long.

The beam calorimeter in the forward region of the ILC detectors will be hit by a large amount of electron-positron pairs originating from beamstrahlung, a new phenomenon at the ILC. The by ionization deposited energy in the BeamCal sensor planes can be as high as 10 MGy per year of operation. The FCAL collaboration investigates different alternatives as possible sensor materials: polycrystalline and single crystal CVD diamond and GaAs. The investigation of these materials includes the measurement of the charge collection distance and the radiation hardness against irradiation with 10 MeV electrons in a test beam to doses of several MGy.

The instrumentation of the very forward region of the ILC detectors is challenging. At lowest polar angles a beam calorimeter, BeamCal, is foreseen. The main tasks of BeamCal are efficient detection of high energetic particles at lowest angles as well as monitoring of the beam collisions. A large background of electron-positron pairs generated by beamstrahlung leads to an energy deposition of 10-20 TeV per bunch crossing in BeamCal. This corresponds locally to doses up to 10 MGy per year of electromagnetic radiation. BeamCal is a compact sandwich calorimeter. Tungsten is the absorber and polycrystalline CVD diamond is under study as the sensor material to allow the operation in this harsh radiation environment. The pCVD diamond sensors under investigation are from different manufacturers fabricated usually on 4 inch wafers. We study the charge collection efficiencies of the diamond sensors as function of the applied electric field and of the absorbed dose. In our application the homogeneity and linearity of the response are of critical importance. In a first test beam period we investigated the linearity of the response of different diamond sensors up to particle fluences of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sup> MIP/(cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> times 10 ns). In a second test beam a high intensity beam of 10 MeV electrons was used to irradiate the diamond sensors and to investigate the behavior of the charge collection efficiency up to doses of several MGy.

Abstract As a result of the high luminosity phase of the SLHC, for CMS a tracking system with very high granularity is mandatory and the sensors will have to withstand an extreme radiation environment of up to 10 16  part/ 2 . On this basis, a new geometry with silicon short strip sensors (strixels) is proposed. To understand their performances, test geometries are developed whose parameters can be verified and optimized using simulation of semiconductor structures. We have used the TCAD-ISE (SYNOPSYS package) software in order to simulate the main electrical parameters of different strip geometries, for p-in-n-type wafers.

A proposal is described to upgrade the existing H1 tracking detector by a semiconductor backward tracking telescope consisting of 8 beam-concentric disks to measure the gluon and quark distribution functions at very low Bjorken x. Each disk comprises three planes of strip and pad silicon detectors made of 4-in wafers in order to determine the polar angle and the transverse momentum, and to trigger on deep inelastically scattered electrons. The simulation work and the layout constraints on the semiconductors are discussed. The technical and electronics design of the trigger is reviewed. It has to cope with very high beam background rates and the HERA bunch crossing rate of 10.4 MHz.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

We present measurements of both transport and quantum mobility in a GaAs/AlGaAs heterostructure as a function of the electron concentration, in a range where the second subband becomes occupied. From these measurements we observe a drop in the mobilities at the onset of the second subband. The second subband influences the electrical transport properties by intersubband scattering and screening effects. The individual contribution of these effects determines the height and sign of the step in the mobility and depends on the spatial overlap between the wavefunctions of both subbands, as we show with theoretical model calculations.

The H1 detector at HERA at DESY presently undergoes a major upgrade. In this context silicon strip detectors have been installed at the beginning of 1995. The high bunch crossing frequency of HERA (10.4 MHz) demands a novel readout architecture which includes pipelining, signal processing and data reduction at a very early stage. The front end readout is hierarchically organized. The detector elements are read out by the APC chip which contains an analog pipeline and performs first background subtraction. Up to five readout chips are controlled by a Decoder Chip. The readout processor module (OnSiRoC) operates the detectors, controls the Decoder Chips and performs a first level data reduction. The paper describes the readout architecture of the H1 silicon detectors and performance data of the complete readout chain.

Abstract The determination of the strong coupling constant $$\alpha _{\mathrm{s}} (m_{\mathrm{Z}})$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>α</mml:mi> <mml:mi>s</mml:mi> </mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>Z</mml:mi> </mml:msub> <mml:mo>)</mml:mo> </mml:mrow> </mml:mrow> </mml:math> from H1 inclusive and dijet cross section data [1] exploits perturbative QCD predictions in next-to-next-to-leading order (NNLO) [2–4]. An implementation error in the NNLO predictions was found [4] which changes the numerical values of the predictions and the resulting values of the fits. Using the corrected NNLO predictions together with inclusive jet and dijet data, the strong coupling constant is determined to be $$\alpha _{\mathrm{s}} (m_{\mathrm{Z}}) =0.1166\,(19)_{\mathrm{exp}}\,(24)_{\mathrm{th}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>α</mml:mi> <mml:mi>s</mml:mi> </mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>Z</mml:mi> </mml:msub> <mml:mo>)</mml:mo> </mml:mrow> <mml:mo>=</mml:mo> <mml:mn>0.1166</mml:mn> <mml:mspace /> <mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>19</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> <mml:mi>exp</mml:mi> </mml:msub> <mml:mspace /> <mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>24</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> <mml:mi>th</mml:mi> </mml:msub> </mml:mrow> </mml:math> . Complementarily, $$\alpha _{\mathrm{s}} (m_{\mathrm{Z}})$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>α</mml:mi> <mml:mi>s</mml:mi> </mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>Z</mml:mi> </mml:msub> <mml:mo>)</mml:mo> </mml:mrow> </mml:mrow> </mml:math> is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value $$\alpha _{\mathrm{s}} (m_{\mathrm{Z}}) =0.1147\,(25)_{\mathrm{tot}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>α</mml:mi> <mml:mi>s</mml:mi> </mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:msub> <mml:mi>m</mml:mi> <mml:mi>Z</mml:mi> </mml:msub> <mml:mo>)</mml:mo> </mml:mrow> <mml:mo>=</mml:mo> <mml:mn>0.1147</mml:mn> <mml:mspace /> <mml:msub> <mml:mrow> <mml:mo>(</mml:mo> <mml:mn>25</mml:mn> <mml:mo>)</mml:mo> </mml:mrow> <mml:mi>tot</mml:mi> </mml:msub> </mml:mrow> </mml:math> obtained is consistent with the determination from jet data alone. Corrected figures and numerical results are provided and the discussion is adapted accordingly.

Two different technologies are considered for the Beam Calorimeters of the ILC detector. Simulation studies of the performance have been done for a diamond-tungsten sandwich calorimeter and for a homogeneous heavy element crystal calorimeter with optical fiber readout. Studies of the stability and the linearity of a polycrystalline diamond were done for the diamond-tungsten option. For the heavy crystal option the light yield reduction due to the wavelength shifting fiber readout was studied.

Two special calorimeters are foreseen for the instrumentation of the very forward region of an ILC or CLIC detector; a luminometer (LumiCal) designed to measure the rate of low angle Bhabha scattering events with a precision better than 10$^{-3}$ at the ILC and 10$^{-2}$ at CLIC, and a low polar-angle calorimeter (BeamCal). The latter will be hit by a large amount of beamstrahlung remnants. The intensity and the spatial shape of these depositions will provide a fast luminosity estimate, as well as determination of beam parameters. The sensors of this calorimeter must be radiation-hard. Both devices will improve the e.m. hermeticity of the detector in the search for new particles. Finely segmented and very compact electromagnetic calorimeters will match these requirements. Due to the high occupancy, fast front-end electronics will be needed. Monte Carlo studies were performed to investigate the impact of beam-beam interactions and physics background processes on the luminosity measurement, and of beamstrahlung on the performance of BeamCal, as well as to optimise the design of both calorimeters. Dedicated sensors, front-end and ADC ASICs have been designed for the ILC and prototypes are available. Prototypes of sensor planes fully assembled with readout electronics have been studied in electron beams.

Detector-plane prototypes of the very forward calorimetry of a future detector at an e+e- collider have been built and their performance was measured in an electron beam. The detector plane comprises silicon or GaAs pad sensors, dedicated front-end and ADC ASICs, and an FPGA for data concentration. Measurements of the signal-to-noise ratio and the response as a function of the position of the sensor are presented. A deconvolution method is successfully applied, and a comparison of the measured shower shape as a function of the absorber depth with a Monte-Carlo simulation is given.

Diamond detectors are used as beam loss and luminosity monitors for CMS and LHC. A time resolution in the nanosecond range allows to detect beam losses and luminosities of single bunches. The radiation hardness and negligible temperature dependence allow the usage of diamond sensors in high radiationfields without cooling. Two different diamond detector types are installed at LHC and CMS. One is based on pcCVD (polycrystalline chemical vapor deposition) diamonds and installed at different locations in the LHC tunnel for beam loss monitoring. Measurements of these detectors are used to perform a bunch-by-bunch beam loss analysis. They allow to disentangle the origin of beam losses. The second type uses scCVD (single crystal chemical vapor deposition) diamonds and is located inside CMS for van-der-Meer scan, beam halo and online luminosity monitoring and around the LHC tunnel for beam loss observation. Results on the performance of these detectors will be presented and examples of the use for analyzing the beam conditions will be given. In order to persist the enhanced requirements of the LHC after the long shutdown, e.g. higher luminosity, an upgrade of the detectors is required. The concept of the new detectors will be presented and first results will be shown.

The Beam Halo Monitor (BHM) for FLASH (FreeElectron LASer in Hamburg) based on pCVD diamond and monocrystalline sapphire sensors has been successfully commissioned and is in operation. It is a part of the beam dump diagnostics system purposed to ensure safe beam dumping. The description of the BHM is given and the results on the performance obtained during its operation are reported in this paper.