S. Bianco

We have searched for a deeply bound kaonic state by using the FINUDA spectrometer installed at the ${e}^{+}{e}^{\ensuremath{-}}$ collider $\mathrm{DA}\ensuremath{\Phi}\mathrm{NE}$. Almost monochromatic ${K}^{\ensuremath{-}}$'s produced through the decay of $\ensuremath{\phi}(1020)$ mesons are used to observe ${K}^{\ensuremath{-}}$ absorption reactions stopped on very thin nuclear targets. Taking this unique advantage, we have succeeded to detect a kaon-bound state ${K}^{\ensuremath{-}}pp$ through its two-body decay into a $\ensuremath{\Lambda}$ hyperon and a proton. The binding energy and the decay width are determined from the invariant-mass distribution as ${115}_{\ensuremath{-}5}^{+6}(\mathrm{stat}{)}_{\ensuremath{-}4}^{+3}(\mathrm{syst})\text{ }\mathrm{MeV}$ and ${67}_{\ensuremath{-}11}^{+14}(\mathrm{stat}{)}_{\ensuremath{-}3}^{+2}(\mathrm{syst})\text{ }\mathrm{MeV}$, respectively.

The narrow dip observed at 1.9 GeV/c2 by the Fermilab experiment E687 in diffractive photoproduction of 3π+3π− is examined. The E687 data are refitted, a mechanism is proposed to explain why this resonance appears as a dip, and possible interpretations are discussed.

The magnetic spectrometer and charged particle tracking system used in Fermilab experiment 687 to study the photoproduction and decay of charm particles are described in detail. The photons are produced by a wideband electron beam which can operate at energies up to 600 GeV/c. The spectrometer consists of a high resolution silicon microstrip detector, a large aperture dipole magnet, proportional chambers, a second large aperture dipole, and more proportional chambers. Three multi-cell threshold Cherenkov counters provide charged particle identification. The tracking system is capable of resolving the secondary decay vertices of charm and beauty mesons and baryons from the primary interaction vertex. It also determines the invariant mass of the multibody final states of particles containing heavy quarks with excellent resolution. The particle identification system allows one to identify kaons and protons present in these final states clearly. This collection of detectors produces very clean signals for charm particles and permits one to make many cross checks of the apparatus. The performance is illustrated for a variety of charm signals. Of particular interest is a description of the tracking through the silicon microstrip detector and its use in isolating downstream decay vertices. Two complementary approaches to the reconstruction of secondary decay vertices are presented and insight is gained by comparing their strengths and weaknesses.

Using data from the FOCUS experiment we analyze the D+π− and D0π+ invariant mass distributions. We measure the D2∗0 mass MD2∗0=(2464.5±1.1±1.9)MeV/c2 and width ΓD2∗0=(38.7±5.3±2.9)MeV/c2, and the D2∗+ mass MD2∗+=(2467.6±1.5±0.76)MeV/c2 and width ΓD2∗+=(34.1±6.5±4.2)MeV/c2. We find evidence for broad structures over background in both the neutral and charged final state. If each is interpreted as evidence for a single L=1, jq=1/2 excited charm meson resonance, the masses and widths are M1/20=(2407±21±35)MeV/c2, Γ1/20=(240±55±59)MeV/c2, and M1/2+=(2403±14±35)MeV/c2, Γ1/2+=(283±24±34)MeV/c2, respectively.

Chiral symmetry and its spontaneous breaking play an important role both in the light hadron and heavy hadron systems. The chiral perturbation theory (χPT) is the low energy effective field theory of the Quantum Chromodynamics. In this work, we shall review the investigations on the chiral corrections to the properties of the heavy mesons and baryons within the framework of χPT. We will also review the scatterings of the light pseudoscalar mesons and heavy hadrons, through which many new resonances such as the Ds0∗(2317) could be understood.Moreover, many new hadron states were observed experimentally in the past decades. A large group of these states is near-threshold resonances, such as the charged charmoniumlike Zc and Zcs states, bottomoniumlike Zb states, hidden-charm pentaquark Pc and Pcs states and the doubly charmed Tcc state, etc. They are very good candidates of the loosely bound molecular states composed of a pair of charmed (bottom) hadrons, which are very similar to the loosely bound deuteron. The modern nuclear force was built upon the chiral effective field theory (χEFT), which is the extension of the χPT to the systems with two matter fields. The long-range and medium-long-range interactions between two nucleons arise from the single- and double-pion exchange respectively, which are well constrained by the chiral symmetry and its spontaneous breaking. The short-distance interactions can be described by the low energy constants. Such a framework works very well for the nucleon–nucleon scattering and nuclei. In this work, we will perform an extensive review of the progress on the heavy hadronic molecular states within the framework of χEFT. We shall emphasize that the same chiral dynamics not only govern the nuclei and forms the deuteron, but also dictates the shallow bound states or resonances composed of two heavy hadrons.

Gas detectors for elementary particles require F-based gases for optimal performance. Recent regulations demand the use of environmentally unfriendly F-based gases to be limited or banned. This work studies properties of potential eco-friendly gas replacements by computing the physical and chemical parameters relevant for use as detector media, and suggests candidates to be considered for experimental investigation.

The search for a novel technology able to detect and reconstruct nuclear and electron recoil events with the energy of a few keV has become more and more important now that large regions of high-mass dark matter (DM) candidates have been excluded. Moreover, a detector sensitive to incoming particle direction will be crucial in the case of DM discovery to open the possibility of studying its properties. Gaseous time projection chambers (TPC) with optical readout are very promising detectors combining the detailed event information provided by the TPC technique with the high sensitivity and granularity of latest-generation scientific light sensors. The CYGNO experiment (a CYGNus module with Optical readout) aims to exploit the optical readout approach of multiple-GEM structures in large volume TPCs for the study of rare events as interactions of low-mass DM or solar neutrinos. The combined use of high-granularity sCMOS cameras and fast light sensors allows the reconstruction of the 3D direction of the tracks, offering good energy resolution and very high sensitivity in the few keV energy range, together with a very good particle identification useful for distinguishing nuclear recoils from electronic recoils. This experiment is part of the CYGNUS proto-collaboration, which aims at constructing a network of underground observatories for directional DM search. A one cubic meter demonstrator is expected to be built in 2022/23 aiming at a larger scale apparatus (30 m3–100 m3) at a later stage.

We have performed a search for CPT violation in neutral charm meson oscillations. While flavor mixing in the charm sector is predicted to be small by the Standard Model, it is still possible to investigate CPT violation through a study of the proper time dependence of a CPT asymmetry in right-sign decay rates for D0→K−π+ and D0→K+π−. This asymmetry is related to the CPT violating complex parameter ξ and the mixing parameters x and y: ACPT∝(Reξ)y−(Imξ)x. Our 95% confidence level limit is −0.0068<(Reξ)y−(Imξ)x<0.0234. Within the framework of the Standard Model Extension incorporating general CPT violation, we also find 95% confidence level limits for the expressions involving coefficients of Lorentz violation of (−2.8<N(x,y,δ)(Δa0+0.6ΔaZ)<4.8)×10−16 GeV, (−7.0<N(x,y,δ)ΔaX<3.8)×10−16 GeV, and (−7.0<N(x,y,δ)ΔaY<3.8)×10−16 GeV, where N(x,y,δ) is the factor which incorporates mixing parameters x, y and the doubly Cabibbo-suppressed to Cabibbo-favored relative strong phase δ.

Λ-hypernuclei are produced and studied, with the FINUDA spectrometer, for the first time at an e+e− collider: DAΦNE, the Frascati ϕ-factory. The slow negative kaons from ϕ(1020) decay are stopped in thin (0.2 g/cm2) nuclear targets, and Λ-hypernuclei formation is detected by measuring the momentum of the outgoing π−. A preliminary analysis on 12ΛC shows an energy resolution of 1.29 MeV FWHM on the hypernuclear levels, the best obtained so far with magnetic spectrometers at hadron facilities. Capture rates for the ground state and the excited ones are reported, and compared with previous experiments.

Using a high statistics sample of photoproduced charm particles from the FOCUS experiment at Fermilab, we compare the lifetimes of neutral D mesons decaying via D0 to K- pi+ and K- K+ to measure the lifetime differences between CP even and CP odd final states. These measurements bear on the phenomenology of D0 - D0bar mixing. If the D0 to K-pi+ is an equal mixture of CP even and CP odd eigenstates, we measure yCP = 0.0342 \pm 0.0139 \pm 0.0074.

Using a large sample of charm semileptonic decays collected by the FOCUS photoproduction experiment at Fermilab, we present evidence for a small, even spin K−π+ amplitude that interferes with the dominant K̄∗0 component in the D+→K−π+μ+ν final state. Although this interference significantly distorts the D+→K−π+μ+ν decay angular distributions, the new amplitude creates only a very small distortion to the observed kaon pion mass distribution when integrated over the other kinematic variables describing the decay. Our data can be described by K̄∗0 interference with either a constant amplitude or broad spin zero resonance.

Analysis of three D → Kππ Dalitz plots is presented using data collected by the Fermilab high energy photoproduction experiment E687. Our data are fit to a model consisting of a sum of Breit-Wigner amplitudes for the intermediate two-body resonant decay modes and a constant term for the nonresonant contribution. We extract branching fractions and relative phases and compare them to the results obtained in other experiments. Although this model qualitatively reproduces many features of our data, statistically significant discrepancies are observed in some of our fits.

FOCUS results from Dalitz plot analyses of D+s and D+ to π+π−π+ are presented. The K-matrix formalism is applied to charm decays for the first time, which allows us to fully exploit the already existing knowledge coming from light-meson spectroscopy experiments. In particular all the measured dynamics of the S-wave ππ scattering, characterized by broad/overlapping resonances and large non-resonant background, can be properly included. This Letter studies the extent to which the K-matrix approach is able to reproduce the observed Dalitz plot and thus help us to understand the underlying dynamics. The results are discussed along with their possible implications for the controversial σ meson.

Reconstruction of posttraumatic bone defects represents a difficult challenge. The induced membrane technique is an effective two-stage procedure for bone defect reconstruction. To overcome the problems of autologous bone grafting, different graft substitutes have been investigated. The aim of the present study is to evaluate our clinical experience in reconstruction of critical posttraumatic bone defects using an induced membrane technique based on a combination of autologous graft and allograft (cancellous bone) enriched with platelet-rich plasma (PRP) and bone marrow concentrate aspirate (BMCA).Between 2009 and 2014, we reconstructed 18 posttraumatic bone defects in 16 patients. Their average length was 6.4 cm (range 1.6-13.2 cm). The defect location was the femur in nine cases (50%), the tibia in eight (44%) cases, and the humerus in one (6%) case. In all cases, we used a combination of autologous and cancellous allograft graft enriched with PRP and BMCA. Bone fixation was achieved using intramedullary nailing in 2 cases (11%), plating in 15 cases (66%), and external fixation in 1 case (6%).Both clinical and radiographic union were achieved in 13 (72%) cases (13 patients). Five (28%) cases (four patients) developed nonunion. Nonunion was observed in two of eight (25%) tibial defects and in three (33%) of nine femoral defects (ns). Three of 4 (75%) double defects had delayed union, whereas 2 of 14 (14%) single defects did not heal (p = 0.016). The average length of the 13 defects that united was 6 cm (range 1.6-11.8 cm), while the length of the 5 defects that did not unite was 10.3 cm (range 6-13.2 cm) (p = 0.009).In this series using an induced membrane technique based on a combination of autograft and allograft enriched with BMCA and PRP, the healing rate was lower than in other series where autologous bone graft alone was employed. Nonunion was more frequent in longer and double defects. Further research aimed at developing effective alternative options to autogenous cancellous bone graft is desirable.III.

We describe the algorithm used to identify charged tracks in the fixed-target charm-photoproduction experiment FOCUS.

Momenta spectra of protons emitted following the capture of K− in 6Li and 12C have been measured with 1% resolution. The 12C spectrum is smooth whereas for 6Li a well defined peak appears at about 500MeV/c. The first observation of a structure in this region was identified as a strange tribaryon or, possibly, a K¯-nuclear state. The peak is correlated with a π− coming from Σ− decay in flight, selected by setting the π momentum larger than 275MeV/c. The Σ− could be produced, together with a 500MeV/c proton, by the capture of a K− in a deuteron-cluster substructure of the 6Li nucleus. The capture rate for such a reaction is (1.62±0.23stat−0.44+0.71(sys))%/Kstop−, in agreement with the existing observations on 4He targets and with the hypothesis that the 6Li nucleus can be interpreted as a (d+α) cluster.

Using a large sample of D0→K−μ+ν and D0→π−μ+ν decays collected by the FOCUS photoproduction experiment at Fermilab, we present new measurements of the q2 dependence for the f+(q2) form factor. These measured f+(q2) form factors are fit to common parameterizations such as the pole dominance form and compared to recent unquenched Lattice QCD calculations. We find mpole=1.93±0.05±0.03GeV/c2 for D0→K−μ+ν and mpole=1.91−0.15+0.30±0.07GeV/c2 for D0→π−μ+ν and f−(K)(0)/f+(K)(0)=−1.7−1.4+1.5±0.3.

Correlated Λd pairs emitted after the absorption of negative kaons at rest Kstop−A→ΛdA′ in light nuclei 6Li and 12C are studied. Λ-hyperons and deuterons are found to be preferentially emitted in opposite directions. The Λd invariant mass spectrum of 6Li shows a bump whose mass is 3251±6 MeV/c2. The bump mass (binding energy), width and yield are reported. The appearance of a bump is discussed in the realm of the [K¯3N] clustering process in nuclei. The experiment was performed with the FINUDA spectrometer at DAΦNE (LNF).

Using data collected by the high-energy photoproduction experiment FOCUS at Fermilab we performed a Dalitz plot analysis of the Cabibbo favored decay D+→K−π+π+. This study uses 53653 Dalitz-plot events with a signal fraction of ∼97%, and represents the highest statistics, most complete Dalitz plot analysis for this channel. Results are presented and discussed using two different formalisms. The first is a simple sum of Breit–Wigner functions with freely fitted masses and widths. It is the model traditionally adopted and serves as comparison with the already published analyses. The second uses a K-matrix approach for the dominant S-wave, in which the parameters are fixed by first fitting Kπ scattering data and continued to threshold by Chiral Perturbation Theory. We show that the Dalitz plot distribution for this decay is consistent with the assumption of two-body dominance of the final state interactions and the description of these interactions is in agreement with other data on the Kπ final state.

In view of an upgrade of the CMS experiment, the GEM for CMS collaboration is performing feasibility studies on employing Triple-GEM detectors for the high-η region (1.6–2.4) of the CMS endcaps. A detailed review of the development and characterization of the CMS full-size prototype baseline detector will be presented. GEMs have excellent spatial and time resolution, high rate capability and radiation hardness, they are an appealing option for simultaneously enhancing muon tracking and triggering capabilities in the high-η region. The GEM for CMS collaboration has studied the performance of small and full-size prototype detectors during several test beam campaigns in order to validate new technologies and techniques in view of a mass production for CMS experiment. Results from measurements with x-rays and from test beam campaigns at the CERN SPS will be shown from both small and large prototypes.

The CYGNO project has the goal to use a gaseous TPC with optical readout to detect dark matter and solar neutrinos with low energy threshold and directionality. The CYGNO demonstrator will consist of 1 m 3 volume filled with He:CF 4 gas mixture at atmospheric pressure. Optical readout with high granularity CMOS sensors, combined with fast light detectors, will provide a detailed reconstruction of the event topology. This will allow to discriminate the nuclear recoil signal from the background, mainly represented by low energy electron recoils induced by radioactivity. Thanks to the high reconstruction efficiency, CYGNO will be sensitive to low mass dark matter, and will have the potential to overcome the neutrino floor, that ultimately limits non-directional dark matter searches.

The series of upgrades to the Large Hadron Collider, culminating in the High Luminosity Large Hadron Collider, will enable a significant expansion of the physics program of the CMS experiment. However, the accelerator upgrades will also make the experimental conditions more challenging, with implications for detector operations, triggering, and data analysis. The luminosity of the proton-proton collisions is expected to exceed $2-3\times10^{34}$~cm$^{-2}$s$^{-1}$ for Run 3 (starting in 2022), and it will be at least $5\times10^{34}$~cm$^{-2}$s$^{-1}$ when the High Luminosity Large Hadron Collider is completed for Run 4. These conditions will affect muon triggering, identification, and measurement, which are critical capabilities of the experiment. To address these challenges, additional muon detectors are being installed in the CMS endcaps, based on Gas Electron Multiplier technology. For this purpose, 161 large triple-Gas Electron Multiplier detectors have been constructed and tested. Installation of these devices began in 2019 with the GE1/1 station and will be followed by two additional stations, GE2/1 and ME0, to be installed in 2023 and 2026, respectively. The assembly and quality control of the GE1/1 detectors were distributed across several production sites around the world. We motivate and discuss the quality control procedures that were developed to standardize the performance of the detectors, and we present the final results of the production. Out of 161 detectors produced, 156 detectors passed all tests, and 144 detectors are now installed in the CMS experiment. The various visual inspections, gas tightness tests, intrinsic noise rate characterizations, and effective gas gain and response uniformity tests allowed the project to achieve this high success rate.

Fermilab high-energy photoproduction experiment E687 provides a high statistics sample of the decay mode D+ → K∗0μ+ν (charge conjugates are implied). Our analysis yields a branching ratio of Γ (D+ → K∗0μ+ν)Γ (D+ → K−π+π+) = 0.56±0.04±0.06. The ratios of the form factors governing the decay are measured to be Rν = 1.74 ±0.27±0.28 and R2 = 0.78±0.18±0.10, implying a polarization of ΓlΓt = 1.20±0.13 ±0.13 for the electron decay. Finally, we report new limits on the decay modes D+ → K−π+μ+ν (nonresonent) and D+ → K∗0π0μ+ν.

An observation of an excited ${\mathrm{\ensuremath{\Lambda}}}_{\mathit{c}}^{+\mathrm{*}}$ baryon decaying to ${\mathrm{\ensuremath{\Lambda}}}_{\mathit{c}}^{+}$${\mathrm{\ensuremath{\pi}}}^{+}$${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$, with ${\mathrm{\ensuremath{\Lambda}}}_{\mathit{c}}^{+}$\ensuremath{\rightarrow}${\mathit{pK}}^{\mathrm{\ensuremath{-}}}$${\mathrm{\ensuremath{\pi}}}^{+}$, is presented. We reconstruct 39.7\ifmmode\pm\else\textpm\fi{}8.7${\mathrm{\ensuremath{\Lambda}}}_{\mathit{c}}^{+\mathrm{*}}$ baryons with a mass of 340.4\ifmmode\pm\else\textpm\fi{}0.6\ifmmode\pm\else\textpm\fi{}0.3 MeV/${\mathit{c}}^{2}$ above the ${\mathrm{\ensuremath{\Lambda}}}_{\mathit{c}}^{+}$ mass. The upper limit on the resonant branching ratio is B(${\mathrm{\ensuremath{\Lambda}}}_{\mathit{c}}^{+\mathrm{*}}$\ensuremath{\rightarrow}${\mathrm{\ensuremath{\Sigma}}}_{\mathit{c}}$${\mathrm{\ensuremath{\pi}}}^{\ifmmode\pm\else\textpm\fi{}}$)/B(${\mathrm{\ensuremath{\Lambda}}}_{\mathit{c}}^{+\mathrm{*}}$\ensuremath{\rightarrow}${\mathrm{\ensuremath{\Lambda}}}_{\mathit{c}}^{+}$ ${\mathrm{\ensuremath{\pi}}}^{+}$${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$)36% at the 90% confidence level.

Using data from FOCUS (E831) experiment at Fermilab, we present a model independent partial-wave analysis of the K−π+ S-wave amplitude from the decay D+→K−π+π+. The S-wave is a generic complex function to be determined directly from the data fit. The P- and D-waves are parameterized by a sum of Breit–Wigner amplitudes. The measurement of the S-wave amplitude covers the whole elastic range of the K−π+ system.

Due to the recent restrictions deriving from the application of the Kyoto protocol, the main components of the gas mixtures presently used in the Resistive Plate Chambers systems of the LHC experiments will be most probably phased out of production in the coming years. Identifying possible replacements with the adequate characteristics requires an intense R&D, which was recently started, also in collaborations across the various experiments. Possible candidates have been proposed and are thoroughly investigated. Some tests on one of the most promising candidate - HFO-1234ze, an allotropic form of tetrafluoropropane- have already been reported. Here an innovative approach, based on the use of Helium, to solve the problems related to the too elevate operating voltage of HFO-1234ze based gas mixtures, is discussed and the relative first results are shown.

Time Projection Chambers (TPCs) working in combination with Gas Electron Multipliers (GEMs) produce a very sensitive detector capable of observing low energy events. This is achieved by capturing photons generated during the GEM electron multiplication process by means of a high-resolution camera. The CYGNO experiment has recently developed a TPC Triple GEM detector coupled to a low noise and high spatial resolution CMOS sensor. For the image analysis, an algorithm based on an adapted version of the well-known DBSCAN was implemented, called iDBSCAN. In this paper a description of the iDBSCAN algorithm is given, including test and validation of its parameters, and a comparison with DBSCAN itself and a widely used algorithm known as Nearest Neighbor Clustering (NNC). The results show that the adapted version of DBSCAN is capable of providing full signal detection efficiency and very good energy resolution while improving the detector background rejection.

A narrow dip structure has been observed at 1.9 GeV/c2 in a study of diffractive photoproduction of the 3π+3π− final state performed by the Fermilab experiment E687.

Amplitude analyses of the D+ and Ds+ → K+K−π+ Dalitz plots are presented using data collected by the Fermilab high energy photoproduction experiment E687. Our data are fit to a model consisting of a sum of Breit-Wigner amplitudes for the intermediate two-body resonant decay modes. We extract decay fractions and relative phases. These results are used to infer new branching ratios for D+ → K+K−π+ inclusive as well as the Φπ+ and K∗(892)0K+ channels.

After briefly recapitulating the history of the charm quantum number we sketch the experimental environments and instruments employed to study the behaviour of charm hadrons and then describe the theoretical tools for treating charm dynamics. We discuss a wide range of inclusive production processes before analyzing the spectroscopy of hadrons with hidden and open charm and the weak lifetimes of charm mesons and baryons. Then we address leptonic, exclusive semileptonic and nonleptonic charm decays. Finally we treat $D^0 - \bar D^0$ oscillations and CP (and CPT) violation before concluding with some comments on charm and the quark-gluon plasma. We will make the case that future studies of charm dynamics -- in particular of CP violation -- can reveal the presence of New Physics. The experimental sensitivity has only recently reached a level where this could reasonably happen, yet only as the result of dedicated efforts. This review is meant to be both a pedagogical introduction for the young scholar and a useful reference for the experienced researcher. We aim for a self-contained description of the fundamental features while providing a guide through the literature for more technical issues.

Measurements of elastic photoproduction cross sections for the J/ψ meson from 100 GeV to 375 GeV are presented. The results indicate that the cross section increases slowly in this range. The shape of the energy dependence agrees well with the photon-gluon fusion model prediction.

The large-volume detector (LVD) which will be installed in Hall A of the Gran Sasso Laboratory can be defined as an underground observatory devoted to neutrino astronomy and to the measurement of the penetrating components of cosmic rays. The detector consists of two major parts: the tracking system and the scintillator system. It is specifically designed to permit a multipurpose experiment allowing the detection of neutrino interaction inside the detector and the detection of omnidirectional mu-mesons and the measurement of their trajectories and direction of flight.

The results of a measurement of the proton spectra following the non-mesonic weak decay of 5ΛHe, 7ΛLi and 12ΛC are presented and discussed. The experiment was performed at the (e+ e−) collider DAΦNE at Laboratori Nazionale di Frascati of INFN. It is the first measurement for 7ΛLi, and for all the spectra the lower limit on the energy of the protons is 15 MeV, never reached before. All the spectra show a similar shape, namely a peak at around 80 MeV as expected for the free Λp→np weak reaction, with a low energy rise that should be due to final state interactions and/or two-nucleon induced weak processes. The decay spectrum of 5ΛHe is somehow similar to the ones reported by previous measurements and theoretical calculations, but the same does not happen for the 12ΛC one.

Optical readout of large Time Projection Chambers (TPCs) with multiple Gas Electron Multipliers (GEMs) amplification stages has shown to provide very interesting performances for high energy particle tracking. Proposed applications for low-energy and rare event studies, such as Dark Matter search, ask for demanding performance in the keV energy range. The performance of such a readout was studied in details as a function of the electric field configuration and GEM gain by using a 55Fe source within a 7 litre sensitive volume detector developed as a part of the R&D for the CYGNUS project. Results reported in this paper show that the low noise level of the sensor allows to operate with a 2 keV threshold while keeping a rate of fake-events lesser than 10 per year. In this configuration, a detection efficiency well above 95% along with an energy resolution (σ) of 18% is obtained for the 5.9 keV photons demonstrating the very promising capabilities of this technique.

The search for a novel technology able to detect and reconstruct nuclear recoil events in the keV energy range has become more and more important as long as vast regions of high mass WIMP-like Dark Matter candidate have been excluded. Gaseous Time Projection Chambers (TPC) with optical readout are very promising candidate combining the complete event information provided by the TPC technique to the high sensitivity and granularity of last generation scientific light sensors. A TPC with an amplification at the anode obtained with Gas Electron Multipliers (GEM) was tested at the Laboratori Nazionali di Frascati. Photons and neutrons from radioactive sources were employed to induce recoiling nuclei and electrons with kinetic energy in the range [1-100] keV. A He-CF4 (60/40) gas mixture was used at atmospheric pressure and the light produced during the multiplication in the GEM channels was acquired by a high position resolution and low noise scientific CMOS camera and a photomultiplier. A multi-stage pattern recognition algorithm based on an advanced clustering technique is presented here. A number of cluster shape observables are used to identify nuclear recoils induced by neutrons originated from a AmBe source against X-ray 55Fe photo-electrons. An efficiency of 18% to detect nuclear recoils with an energy of about 6 keV is reached obtaining at the same time a 96% 55Fe photo-electrons suppression. This makes this optically readout gas TPC a very promising candidate for future investigations of ultra-rare events as directional direct Dark Matter searches.

Coronal holes (CHs) have long been known as one of the main sources of high-speed solar wind streams, but recent evidence suggests that active regions (ARs) also play a significant role as solar wind sources. In this study, we aim to investigate the impact of both CHs and ARs as source regions of the solar wind. Both structures can be identified in extreme ultra-violet (EUV) solar images several days before they become geoeffective. We exploit this relation to construct a model that forecasts the solar wind speed at L1. First, we accurately detect and track the evolution of CHs and ARs over time by employing a segmentation algorithm on solar images. Next, we extract features from the indicated regions in EUV images and magnetograms, such as area and location of the source regions and the corresponding magnetic field configurations. These features, along with solar wind data from previous solar rotations and the current state of the solar cycle, are assimilated over time in a data-driven model that predicts the hourly solar wind speed at L1 four days in advance. During model training, we particularly focus on preserving the distribution of observed solar wind speeds to overcome a common drawback of data-driven solar wind speed prediction models, namely the underprediction of the peak values of solar storms. By adding a suitable regularization to the loss function, we force our model to follow the physical behavior more closely, which results in a significantly improved accuracy for predicting solar storms. Finally, we use our model to draw conclusions about the physical relevance of CHs and ARs for solar wind speed models. The model's performance is evaluated through cross-validation on 14 years of data and compared to other state-of-the-art models.

An amplitude analysis of the D+, Ds+ → π−π+π+ Dalitz plots is presented using data collected by the Fermilab high-energy photoproduction experiment E687. The data are fitted to a model consisting of a sum of relativistic Breit-Wigner amplitudes for the intermediate two-body resonant decay modes plus a flat non-resonant contribution. From the fit we derive decay fractions and relative phases. We also present measurements of Γ(D+→π−π+π+)Γ(D+→K−π+π+) and Γ(Ds+→π−π+π+)Γ(Ds+→K−K+π+).

We report data taken by the LVD Experiment during a live-time period of 11 556 h. We have measured the muon intensity at slant depths of standard rock from about 3000 hg/cm2 to about 20 000 hg/cm2. This is an exclusive study, namely our data include only events containing single muons. This interval of slant depth extends into the region where the dominant source of underground muons seen by LVD is the interaction of atmospheric neutrinos with the rock surrounding LVD. The interesting result is that this flux is independent of slant depth beyond a slant depth of about 14 000 hg/cm2 of standard rock. Due to the unique topology of the Gran Sasso Laboratory the muons beyond about 14 000 hg/cm2 of standard rock are at a zenithal angle near 90°. Hence we have, for this fixed angle, a muon flux which is independent of slant depth. This is direct evidence that this flux is due to atmospheric neutrinos interacting in the rock surrounding LVD. The value of this flux near 90° is (8.3 ± 2.6) × 10−13 cm−2 s−1 sr−1, which is the first reported measurement at a zenithal angle near 90° and for slant depths between 14 000 and 20 000 hg/cm2. Our data cover over five decades of vertical intensity, and can be fit with just three parameters over the full range of our experiment. This is the first time a single experiment reports the parameters of a fit made to the vertical intensity over such a large range of standard rock slant depth. The results are compared with a Monte Carlo simulation which has as one of the two free parameters γπκ, the power index of the differential energy spectrum of the pions and kaons in the atmosphere. This comparison yields a value of 2.75 ± 0.03 for γπκ, where the error includes the systematic uncertainties. Our data are compared to other measurements made in our slant depth interval. We also report the value of the muon flux in Gran Sasso at θ = 90° as a function of the azimuthal angle.

Using data from the FOCUS (E831) experiment, we have searched for T violation in charm meson decays using the four-body decay channels $D^0 \to K^-K^+\pi^-\pi^+$, $D^+ \to K^0_SK^+\pi^-\pi^+$, and $D^+_s \to K^0_SK^+\pi^-\pi^+$. The T violation asymmetry is obtained using triple-product correlations and assuming the validity of the CPT theorem. We find the asymmetry values to be $A_Tviol (D^0) = 0.010 \pm 0.057(stat.) \pm 0.037(syst.)$, $A_Tviol (D^+) = 0.023 \pm 0.062(stat.) \pm 0.022(syst.)$, and $A_Tviol (D^+_s) = -0.036 \pm 0.067(stat.) \pm 0.023(syst.)$. Each measurement is consistent with no T violation. New measurements of the CP asymmetries for some of these decay modes are also presented.

Using a large sample of D+ to K- pi+ mu+ nu decays collected by the FOCUS photoproduction experiment at Fermilab, we present new measurements of two semileptonic form factor ratios: rv and r2. We find rv = 1.504 \pm 0.057 \pm 0.039 and r2 = 0.875 \pm 0.049 \pm 0.064. Our form factor results include the effects of the s-wave interference discussed in a previous paper.

We present a Kπ mass spectrum analysis of the four-body semileptonic charm decay D+→K−π+μ+ν in the range of 0.65GeV/c2<mKπ<1.5GeV/c2. We observe a non-resonant contribution of 5.30±0.74−0.96+0.99% with respect to the total D+→K−π+μ+ν decay. For the K∗(892)0 resonance, we obtain a mass of 895.41±0.32−0.43+0.35MeV/c2, a width of 47.79±0.86−1.06+1.32MeV/c2, and a Blatt–Weisskopf damping factor parameter of 3.96±0.54−0.90+1.31GeV−1. We also report 90% CL upper limits of 4% and 0.64% for the branching ratios Γ(D+→K¯∗(1680)0μ+ν)Γ(D+→K−π+μ+ν) and Γ(D+→K¯0∗(1430)0μ+ν)Γ(D+→K−π+μ+ν), respectively.

We describe a silicon microstrip detector interleaved with segments of a beryllium oxide target which was used in the FOCUS photoproduction experiment at Fermilab. The detector was designed to improve the vertex resolution and to enhance the reconstruction efficiency of short-lived charm particles.

The production of neutron rich $\Lambda$-hypernuclei via the ($K^-_stop$,$\pi^+$) reaction has been studied using data collected with the FINUDA spectrometer at the DA$\Phi$NE $\phi$-factory (LNF). The analysis of the inclusive $\pi^+$ momentum spectra is presented and an upper limit for the production of $^6_\Lambda$H and $^7_\Lambda$H from $^6$Li and $^7$Li, is assessed for the first time.

We present an analysis of the decay D0→K+π− based on FOCUS data. From a sample of 234 signal events, we find a branching ratio of Γ(D0→K+π−)Γ(D0→K−π+)=(0.429−0.061+0.063±0.027)% under the assumptions of no mixing and no CP violation. Allowing for CP violation, we find a branching ratio of (0.429±0.063±0.028)% and a CP asymmetry of 0.18±0.14±0.04. The branching ratio for the case of mixing with no CP violation is (0.381−0.163+0.167±0.092)%. We also present limits on charm mixing.

This paper describes the development of a sensor designed to detect low concentrations of hydrogen fluoride (HF) in gas mixtures. The sensor employs a plastic optical fiber (POF) covered with a thin layer of glass- like material. HF attacks the glass and alters the fiber transmission capability so that the detection simply requires a LED and a photodiode. The coated POF is obtained by means of low-pressure plasma-enhanced chemical vapor deposition that allows the glass-like film to be deposited at low temperature without damaging the fiber core. The developed sensor will be installed in the recirculation gas system of the resistive plate chamber muon detector of the Compact Muon Solenoid experiment at the Large Hadron Collider accelerator of the European Organization for Nuclear Research (CERN).

Over the last decade there were significant advances in the understanding of quantum gravity coupled to point particles in 3D (2+1-dimensional) spacetime. Most notably it is emerging that the theory can be effectively described as a theory of free particles on a momentum space with anti-deSitter geometry and with noncommutative spacetime coordinates of the type $[x^{\mu},x^{\nu}]=i \hbar \ell \varepsilon^{\mu\nu}_{\phantom{\mu\nu}\rho} x^{\rho}$. We here show that the recently proposed relative-locality curved-momentum-space framework is ideally suited for accommodating these structures characteristic of 3D quantum gravity. Through this we obtain an intuitive characterization of the DSR-deformed Poincar\'e symmetries of 3D quantum gravity, and find that the associated relative spacetime locality is of the type producing dual-gravity lensing.

The CMS collaboration considers upgrading the muon forward region which is particularly affected by the high-luminosity conditions at the LHC. The proposal involves Gas Electron Multiplier (GEM) chambers, which are able to handle the extreme particle rates expected in this region along with a high spatial resolution. This allows to combine tracking and triggering capabilities, which will improve the CMS muon High Level Trigger, the muon identification and the track reconstruction. Intense R&D has been going on since 2009 and it has lead to the development of several GEM prototypes and associated detector electronics. These GEM prototypes have been subjected to extensive tests in the laboratory and in test beams at the CERN Super Proton Synchrotron (SPS). This contribution will review the status of the CMS upgrade project with GEMs and its impact on the CMS performance.

Triple-GEM detector technology was recently selected by CMS for a part of the upgrade of its forward muon detector system as GEM detectors provide a stable operation in the high radiation environment expected during the future High-Luminosity phase of the Large Hadron Collider (HL-LHC). In a first step, GEM chambers (detectors) will be installed in the innermost muon endcap station in the $1.6<\left|\eta\right|<2.2$ pseudo-rapidity region, mainly to control level-1 muon trigger rates after the second LHC Long Shutdown. These new chambers will add redundancy to the muon system in the $\eta$-region where the background rates are high, and the bending of the muon trajectories due to the CMS magnetic field is small. A novel construction technique for such chambers has been developed in such a way where foils are mounted onto a single stack and then uniformly stretched mechanically, avoiding the use of spacers and glue inside the active gas volume. We describe the layout, the stretching mechanism and the overall assembly technique of such GEM chambers.

The CYGNO project aims at realizing a one cubic meter gaseous Time Projection Chamber (TPC) equipped with Scientific CMOS (sCMOS) commercial cameras to optically readout Gas Electron Multiplier (GEM) to be operated at the underground of Gran Sasso National Laboratory (LNGS). The purpose of the project is to study the technology needed for a large size gaseous TPC (30–100 m3) operated at atmospheric pressure for the directional search of low mass O(GeV) dark matter and low energy (eg solar) neutrinos astronomy. The roadmap of the project foresees the underground operation of a 50 litres TPC prototype, called LIME, the largest TPC realized with this technology, fully equipped with copper and water shielding. LIME is equivalent to about a 1/20 of the CYGNO demonstrator and aims to validate: The construction materials, the Monte Carlo simulations, the data reconstruction and the particle identification performances at low energy threshold. LIME is under installation at the LNGS and it is supposed to start data taking at the beginning of 2022. The detector description and installation will be presented, as well as the overground performance and limitations that require underground characterization.

The plasmasphere is a region of cold and dense plasma around the Earth, corotating with the Earth. Its plasma density is very dynamic under the influence of the solar wind and it influences several processes such as the GPS navigation, the surface charging of the satellites and the propagation and growth of plasma waves. In this manuscript, we present a new machine-learning model of the equatorial plasma density depending only on the Kp index and the solar-wind properties at the L1 Lagrange point. We call this model PINE-RT as it has been inspired by the recently-introduced PINE (Plasma density in the Inner magnetosphere Neural network-based Empirical) model and it has been developed to run in real-time (RT) in the context of the PAGER project. This project is an EU Horizon 2020 project aiming at forecasting the threats of satellite charging as a consequence of the solar activity 1–2 days ahead. In PAGER, the Kp index and the solar-wind properties at L1 are the inputs which are made available for the plasmasphere modeling. We report here the detailed derivation of the PINE-RT model and its validation and comparison with two state-of-the-art machine-learning and physics-based models. The model is currently running in real-time and its predictions are publicly available.

Results obtained by the RPC ECOgas@GIF++ Collaboration, using Resistive Plate Chambers operated with new, eco-friendly gas mixtures, based on Tetrafluoropropene and carbon dioxide, are shown and discussed in this paper. Tests aimed to assess the performance of this kind of detectors in high-irradiation conditions, analogous to the ones foreseen for the coming years at the Large Hadron Collider experiments, were performed, and demonstrate a performance basically similar to the one obtained with the gas mixtures currently in use, based on Tetrafluoroethane, which is being progressively phased out for its possible contribution to the greenhouse effect. Long term aging tests are also being carried out, with the goal to demonstrate the possibility of using these eco-friendly gas mixtures during the whole High Luminosity phase of the Large Hadron Collider.

The CYGNO project aims to develop a high-precision optical Time Projection Chamber (TPC) for directional Dark Matter search and solar neutrino spettroscopy, to be hosted at Laboratori Nazionali del Gran Sasso (LNGS). The distinctive feature of CYGNO include the exploitation of scientific CMOS cameras and photomultiplier tubes coupled to a Gas Electron Multiplier for amplification within helium-fluorine-based gas mixture at atmospheric pressure. The primary objective of this project is to achieve three-dimentional tracking with head-tail capability and to enhance background rejection down to the keV energy range. This enhancement will significantly improve sensitivity to low Weakly Interacting Massive Particle masses for both Spin-Independent and Spin-Dependent coupling. We provide insights into the commissioning and underground operation of our 50-liter prototype, known as LIME, which represents the largest prototype developed by our collaboration to date. We showcase its capability to measure and identify low-energy nuclear and electron recoils. Additionally, we outline the design and prospects for the development of a funded $\mathcal{O}(1\,\rm{m}^3)$ demonstrator, set to be housed in Hall F of LNGS. Furthermore, we present the physics potential that a future $\mathcal{O}(30\, \rm{m}^3)$ experiment could bring to the field. Lastly, we discuss the results from our collaboration's research and development efforts aimed at maximizing the potential of CYGNO. This includes the recent achievement of negative ion drift operation at atmospheric pressure with optical readout, which was accomplished in synergy with the ERC Consolidator Grant project INITIUM.

The European Union's Horizon 2020 Prediction of Adverse effects of Geomagnetic storms and Energetic Radiation (PAGER) project was successfully concluded in 2023. This project provides real-time space weather forecast initiated from the solar observations as well as predictions of radiation in space and its effects on satellite infrastructure. Real-time predictions of particle radiation and cold plasma density allow for evaluation of surface charging and deep dielectric charging. The project provides a 1-2-day probabilistic and data assimilative forecast of ring current and radiation belt environments, which allows satellite operators to respond to predictions that present a significant threat. As a backbone of the project, we use the state-of-the-art codes that currently exist and adapt existing codes to perform ensemble simulations and uncertainty quantifications. Within PAGER, a number of innovative tools was obtained, including data assimilation and uncertainty quantification, new models of near-Earth electromagnetic wave environment, ensemble predictions of solar wind parameters at L1, and data-driven forecast of the geomangetic Kp index and plasma density. In this presentation, we show the overview of the outcomes and the products obtained within the project. The developed codes may be used in the future for realistic modelling of extreme space weather events.

The High Luminosity LHC phase includes an upgrade to the muon stations for the CMS Experiment. CMS trigger and muon identification performance will be crucial, and it is, therefore, necessary to install new GEM stations to extend acceptance in the high-{\eta} region. An explanation of the quality control test and an update on the status of production will be provided.

The INFN Cloud project was launched at the beginning of 2020, aiming to build a distributed Cloud infrastructure and provide advanced services for the INFN scientific communities. A Platform as a Service (PaaS) was created inside INFN Cloud that allows the experiments to develop and access resources as a Software as a Service (SaaS), and CYGNO is the betatester of this system. The aim of the CYGNO experiment is to realize a large gaseous Time Projection Chamber based on the optical readout of the photons produced in the avalanche multiplication of ionization electrons in a GEM stack. To this extent, CYGNO exploits the progress in commercial scientific Active Pixel Sensors based on Scientific CMOS for Dark Matter search and Solar Neutrino studies. CYGNO, like many other astroparticle experiments, requires a computing model to acquire, store, simulate and analyze data typically far from High Energy Physics (HEP) experiments. Indeed, astroparticle experiments are typically characterized by being less demanding of computing resources with respect to HEP ones but have to deal with unique and unrepeatable data, sometimes collected in extreme conditions, with extensive use of templates and montecarlo, and are often re-calibrated and reconstructed many times for a given data set. Moreover, the varieties and the scale of computing models and requirements are extremely large. In this scenario, the Cloud infrastructure with standardized and optimized services offered to the scientific community could be a useful solution able to match the requirements of many small/medium size experiments. In this work, we will present the CYGNO computing model based on the INFN cloud infrastructure where the experiment software, easily extendible to similar experiments to similar applications on other similar experiments, provides tools as a service to store, archive, analyze, and simulate data.

The KLOE detector is designed primarily for the study of direct CP violation in K0 decays. The electromagnetic calorimeter, EmC, is a most demanding element of the detector. Two prototypes of the EmC (one for the barrel and one for the end-cap region) have been built at Frascati and tested at PSI (Switzerland) using beams of electrons, muons and pions of 40 to 290 MeV/c momentum, and at the Frascati LADON facility using photons of 20 to 80 MeV. We observe excellent linearity from 20 to 290 MeV. The energy resolution is σ(E)/E ∼ 4.4% / ”E(GeV) and the time resolution is ∼ 34 ps/”E(GeV). We found little dependence on incidence angle and entry position. We also determined that some πμ identification is possible.

Using data from FOCUS (E831) experiment at Fermilab, we present a model independent partial-wave analysis of the K−π+ S-wave amplitude from the decay D+→K−π+π+. The S-wave is a generic complex function to be determined directly from the data fit. The P- and D-waves are parameterized by a sum of Breit–Wigner amplitudes. The measurement of the S-wave amplitude covers the whole elastic range of the K−π+ system.

A high statistics sample of photoproduced charm particles from the FOCUS (E831) experiment at Fermilab has been used to search for CP violation in the Cabibbo suppressed decay modes D+→K−K+π+, D0→K−K+ and D0→π−π+. We have measured the following CP asymmetry parameters: ACP(K−K+π+)=+0.006±0.011±0.005, ACP(K−K+)=−0.001±0.022±0.015 and ACP(π−π+)=+0.048±0.039±0.025 where the first error is statistical and the second error is systematic. These asymmetries are consistent with zero with smaller errors than previous measurements.

A high-statistics sample of photoproduced charm from the FOCUS experiment has been used to search for direct CP violation in the decay rates for D+-->K(S)pi+ and D+-->K(S)K+. We have measured the following asymmetry parameters relative to D+-->K-pi+pi+: A(CP)(K(S)pi+) = (-1.6+/-1.5+/-0.9)%, A(CP)(K(S)K+) = (+6.9+/-6.0+/-1.5)%, and A(CP)(K(S)K+) = (+7.1+/-6.1+/-1.2)% relative to D+-->K(S)pi+. We have also measured the relative branching ratios and found Gamma(D+-->K(0)pi+)/Gamma(D+-->K-pi+pi+) = (30.60+/-0.46+/-0.32)%, Gamma(D+-->K(0)K+)/Gamma(D+-->K-pi+pi+) = (6.04+/-0.35+/-0.30)%, and Gamma(D+-->K(0)K+)/Gamma(D+-->K(0)pi+) = (19.96+/-1.19+/-0.96)%.

Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement for the branching ratios of the Cabibbo-suppressed decay modes D0→π−π+ and D0→K−K+. We measured: Γ(D0→K−K+)/Γ(D0→π−π+)=2.81±0.10(stat)±0.06(syst), Γ(D0→K−K+)/Γ(D0→K−π+)=0.0993±0.0014(stat)±0.0014(syst), and Γ(D0→π−π+)/Γ(D0→K−π+)=0.0353±0.0012(stat)±0.0006(syst). These values have been combined with other experimental data to extract the ratios of isospin amplitudes and the phase shifts for the D→KK and D→ππ decay channels.

We review genetic programming principles, their application to FOCUS data samples, and use the method to study the doubly Cabibbo suppressed decay D+ -> K+ pi+ pi- relative to its Cabibbo favored counterpart, D+ -> K- pi+ pi+. We find that this technique is able to improve upon more traditional analysis methods. To our knowledge, this is the first application of the genetic programming technique to High Energy Physics data.

Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement of the weak decay-asymmetry parameter αΛc in Λc+→Λπ+ decay. Comparing particle with antiparticle decays, we obtain the first measurement of the CP violation parameter A≡αΛc+αΛ¯cαΛc−αΛ¯c. We obtain αΛc=−0.78±0.16±0.19 and A=−0.07±0.19±0.24 where errors are statistical and systematic.

The status of the CMS RPC Gas Gain Monitoring (GGM) system developed at the Frascati Laboratory of INFN (Istituto Nazionale di Fisica Nucleare) is reported on. The GGM system is a cosmic ray telescope based on small RPC detectors operated with the same gas mixture used by the CMS RPC system. The GGM gain and efficiency are continuously monitored on-line, thus providing a fast and accurate determination of any shift in working point conditions. The construction details and the first result of GGM commissioning are described.

The muon detection system of the Compact Muon Solenoid experiment at the CERN Large Hadron Collider is based on different technologies for muon tracking and triggering. In particular, the muon system in the endcap disks of the detector consists of Resistive Plate Chambers for triggering and Cathode Strip Chambers for tracking. At present, the endcap muon system is only partially instrumented with the very forward detector region remaining uncovered. In view of a possible future extension of the muon endcap system, we report on a feasibility study on the use of Micro-Pattern Gas Detectors, in particular Gas Electron Multipliers, for both muon triggering and tracking. Results on the construction and characterization of small triple-Gas Electron Multiplier prototype detectors are presented.

Displaced intra-articular calcaneal fractures (DIACF) represent a challenging and controversial issue in traumatology. Conservative treatment has been recommended to avoid surgical problems and complications. The final result, however, is often a painful malunioun of the calcaneus with peroneal impingement. Surgical treatment is gaining acceptance since it offers a chance to restore bone anatomy improving function as long as complications are avoided.We reviewed a series of 59 DIACF treated by a single surgeon during a 9 years period. A clinical and radiological follow-up was obtained in 44 cases (74,6%) (average of 5,5 years; range 2-9). There were 29 males and 15 females with an average age of 54 years (range 25-74). Patients were operated through an extended l-shaped lateral approach and fixation was achieved with lag screws and plate. Outcome measures method included the AOFAS score, the Maryland Foot Score, the Foot Function Index and the SF-36.The average AOFAS score was 80,5 points. The result was excellent in 18 cases (40,9%), good in 14 cases (31,8%), fair in 10 cases (22,7%) and poor in 2 (4,6%). The mean score for pain was 33,5/40 points, for function 40/50 and for alignment 7/10. Pain was absent in 17 cases (38%), 19 patients (43%) had no functional limitations and 11 (25%) could walk on uneven ground without difficulties. The average FFI score was 25/100 points. The average MFS score was 89/100 points. Subtalar motion was reduced. Reconstruction of the calcaneus was anatomic in 20 cases (45,5%) with an improved clinical outcome. Eight patients (17%) had minor wound healing complications. Three patients (6,8%) required a subtalar arthrodesis after the procedure.Ostheosytesis through an extended lateral approach restored bone morphology with a reasonable complications rate. The clinical results were good but a normal function and complete subtalar motion were rarely achieved.

We study the implications of a change of coordinatization of momentum space for theories with curved momentum space. We of course find that after a passive diffeomorphism the theory yields the same physical predictions, as one would expect considering that a simple reparametrization should not change physics. However, it appears that general momentum-space covariance (invariance under active diffeomorphisms of momentum space) cannot be enforced, and within a given set of prescriptions on how the theory should encode momentum-space metric and affine connection the physical predictions do depend on the momentum space background. These conclusions find support in some general arguments and in our quantitative analysis of a much-studied toy model with maximally symmetric (curved) momentum space.

The performance and long term stability of an optically readout Time Projection Chamber with an electron amplification structure based on three Gas Electron Multipliers was studied. He/CF4 based gas mixtures were used in two different proportions (60/40 and 70/30) in a CYGNO prototype with 7 litres sensitive volume. With electrical configurations providing very similar electron gains, an almost full detection efficiency in the whole detector volume was found with both mixtures, while a light yield about 20% larger for the 60/40 was found. The electrostatic stability was tested by monitoring voltages and currents during 25 days. The detector worked in very stable and safe condition for the whole period. In the presence of less CF4, a larger probability of unstable events was clearly detected.

We present evidence for the Ωc0 in a new decay mode Ωc0 → Σ+K−K−π+, for which we find 42.5 ± 8.8 events with a mass of 2699.9 ± 1.5 ± 2.5 MeV/c2. The data are from Fermilab high energy photoproduction experiment E687.

We report the measurement of masses and widths of the following L=1 charm mesons by the E687 Collaboration at Fermilab: a ${\mathit{D}}_{2}^{\mathrm{*}0}$ state of mass (width) 2453\ifmmode\pm\else\textpm\fi{}3\ifmmode\pm\else\textpm\fi{}2 (25\ifmmode\pm\else\textpm\fi{}10\ifmmode\pm\else\textpm\fi{}5) MeV/${\mathit{c}}^{2}$ decaying to ${\mathit{D}}^{+}$${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$, a ${\mathit{D}}_{2}^{\mathrm{*}+}$ state of mass (width) 2453\ifmmode\pm\else\textpm\fi{}3\ifmmode\pm\else\textpm\fi{}2 (23\ifmmode\pm\else\textpm\fi{}9\ifmmode\pm\else\textpm\fi{}5) MeV/${\mathit{c}}^{2}$ decaying to ${\mathit{D}}^{0}$${\mathrm{\ensuremath{\pi}}}^{+}$, a ${\mathit{D}}_{1}^{0}$ state of mass (width) 2422\ifmmode\pm\else\textpm\fi{}2\ifmmode\pm\else\textpm\fi{}2 (15\ifmmode\pm\else\textpm\fi{}8\ifmmode\pm\else\textpm\fi{}4) MeV/${\mathit{c}}^{2}$ decaying to ${\mathit{D}}^{\mathrm{*}+}$${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$, and a ${\mathit{D}}_{\mathit{s}1}^{+}$ state of mass 2535.0\ifmmode\pm\else\textpm\fi{}0.6\ifmmode\pm\else\textpm\fi{}1.0 MeV/${\mathit{c}}^{2}$ and width 3.2 MeV/${\mathit{c}}^{2}$ at 90% confidence level, decaying to ${\mathit{D}}^{\mathrm{*}+}$${\mathit{K}}_{\mathit{s}}^{0}$ and ${\mathit{D}}^{\mathrm{*}0}$${\mathit{K}}^{+}$.

We report evidence of a narrow resonance at a mass of 2705.9 ± 3.3 ± 2.0 MeV/c2 in the final state Ω−π+ and the charge conjugate. The mass and width support the interpretation of a weakly decaying doubly strange charmed baryon, the Ωc0. Limits on the relative branching ratios for Ωc0→Ω−K−π+π+ and Ωc0→Ω−π−π+π+ are also presented.

We describe the various techniques developed in the Fermilab Wideband Experiments, E687 and FOCUS, to reconstruct long-lived states. The techniques all involve modifications to standard tracking techniques and are useful to report for future experiments.

The CMS RPC muon detector utilizes a gas recirculation system called closed loop (CL) to cope with large gas mixture volumes and costs.A systematic study of CL gas purifiers has been carried out over 400 days between July 2008 and August 2009 at CERN in a low-radiation test area, with the use of RPC chambers with currents monitoring, and gas analysis sampling points.The study aimed to fully clarify the presence of pollutants, the chemistry of purifiers used in the CL, and the regeneration procedure.Preliminary results on contaminants release and purifier characterization are reported.

In this work the design of a constant fraction discriminator (CFD) to be used in the VFAT3 chip for the read-out of the triple-GEM detectors of the CMS experiment, is described. A prototype chip containing 8 CFDs was implemented using 130 nm CMOS technology and test results are shown.

We report on the study of charm baryons decaying to Λc+: Λc★+(2625) → Λc+π+π−, Λc★+(2593) → Λc+π+π−, Σc0 → Λc+π− and Σc++ → Λc+π+. We present a confirmation of the state Λc∗+ (2593) and determine its mass difference to be M(Λc★+(2593)) − M(Λc+) = 309.2 ± 0.7 ± 0.3 MeV/c2. We determine the lower limit on the resonant branching ratio to be BR(Λc★+(2593) → Σcπ±Λc★+(2593) → Λc+π+π−) > 0.51 (90% c.l.). We also measure the mass differences M(Σc0) − M(Λc+) = 166.6±0.5±0.6 MeV/c2 and M(Σc++) − M(Λc+) = 167.6±0.6±0.6 MeV/c2. Finally, we measure the relative photoproduction cross sections for Λc★+ and Σc with respect to the (inclusive) photoproduction cross section for Λc+.

We report measurements of charm particle production asymmetries from the Fermilab photoproduction experiment E687. An asymmetry in the rate of production of charm versus anticharm particles is expected to arise primarily from fragmentation effects. We observe statistically significant asymmetries in the photoproduction of D+, D∗+ and D0 mesons and find small (but statistically weak) asymmetries in the production of the Ds+ meson and the Λc+ baryon. Our inclusive photoproduction asymmetries are compared to predictions from nonperturbative models of charm quark fragmentation.

We present a detailed study, done in the framework of the INFN 2006 Roadmap, of the prospects for e+e- physics at the Frascati National Laboratories. The physics case for an e+e- collider running at high luminosity at the φ resonance energy and also reaching a maximum center of mass energy of 2.5 GeV is discussed, together with the specific aspects of a very high luminosity τ-charm factory. Subjects connected to kaon decay physics are not discussed here, being part of another INFN Roadmap working group. The significance of the project and the impact on INFN are also discussed. All the documentation related to the activities of the working group can be found in http://www.roma1.infn.it/people/bini/roadmap.html.

Using data from the FOCUS (E831) experiment at Fermilab, we present new measurements for the Cabibbo-suppressed decay mode D 0 → π -π + π -π + .We measure the branching ratio0022.An amplitude analysis has been performed, a first for this channel, in order to determine the resonant substructure of this decay mode.The dominant component is the decay D 0 → a 1 (1260) + π -, accounting for 60% of the decay rate.The second most dominant contribution comes from the decay D 0 → ρ(770) 0 ρ(770) 0 , with a fraction of 25%.We also study the a 1 (1260) line shape and resonant substructure.Using the helicity formalism for the angular distribution of the decay D 0 → ρ(770) 0 ρ(770) 0 , we measure a longitudinal polarization of P L = (71 ± 4 ± 2)%.

The FINUDA spectrometer, devoted to hypernuclear physics and installed on the DAΦNE two rings collider at the Laboratori Nationali di Frascati, is able to monitor the relevant machine parameters, as luminosity, collision vertexes, c.m. energy and transversal momentum boost, during the process of data taking to study hypernuclear physics without affecting it. The collider parameters relevant to optimize the machine performances to the needs of the experiment are measured both on-line and offline in a run-to-run basis, in an efficient, redundant way, allowing the continuous extraction of reliable and cross-checked information on the machine working conditions.

It was recently realized that Planck-scale momentum-space curvature, which is expected in some approaches to the quantum-gravity problem, can produce dual-curvature lensing, a feature which mainly affects the direction of observation of particles emitted by very distant sources. Several gray areas remain in our understanding of dual-curvature lensing, including the possibility that it might be just a coordinate artifact and the possibility that it might be in some sense a by-product of the better studied dual-curvature redshift. We stress that data reported by the IceCube neutrino telescope should motivate a more vigorous effort of investigation of dual-curvature lensing, and we observe that studies of the recently proposed “<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:mi>ρ</mml:mi></mml:mrow></mml:math>-Minkowski noncommutative spacetime” could be valuable from this perspective. Through a dedicated <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mrow><mml:mi>ρ</mml:mi></mml:mrow></mml:math>-Minkowski analysis, we show that dual-curvature lensing is not merely a coordinate artifact and that it can be present even in theories without dual-curvature redshift.

The operations of Resistive Plate Chambers in LHC experiments require Fluorine based (F-based) gases for optimal performance. Recent European regulations demand the use of environmentally unfriendly F-based gases to be limited or banned. In view of the CMS experiment upgrade, several tests are ongoing to measure the performance of the detector with these new ecological gas mixtures, in terms of efficiency, streamer probability, induced charge and time resolution. Prototype chambers with readout pads and with the standard CMS electronic setup are under test. In this paper preliminary results on performance of RPCs operated with a potential eco-friendly gas candidate 1,3,3,3-Tetrafluoropropene, commercially known as HFO-1234ze, with CO2 and CF3I based gas mixtures are presented and discussed for the possible application in the CMS experiment.

The Time Projection Chamber (TPC) is an ideal candidate to finely study the charged particle ionization in a gaseous medium. Large volume TPCs can be readout with a suitable number of channels offering a complete 3D reconstruction of a charged particle track, that is the sequence of its energy releases in the TPC gas volume. Moreover, He-based TPCs are very promising to study keV energy particles as nuclear recoils, opening the possibility for directional searches of Dark Matter (DM) and the study of Solar Neutrinos (SN). In this paper we report the analysis of the data acquired with a small TPC prototype (named LEMOn) built by the CYGNO collaboration that was exposed to a beam of 450 MeV electrons at the Beam Test Facility of National Laboratories of Frascati. LEMOn is operated with a He-CF4 mixture at atmospheric pressure and is based on a Gas Electron Multipliers amplification stage that produces visible light collected by the high granularity and very good sensitivity of scientific CMOS camera. This type of readout – in conjunction with a fast light detection – allows a 3D reconstruction of the electrons tracks. The electrons are leaving a trail of clusters of ionizations corresponding to a few keV energy release each. Their study leads to predict a keV energy threshold and 1–10 mm longitudinal and 0.1–0.3 mm transverse position resolution (sigma) for nuclear recoils, very promising for the application of optically read out TPC to DM searches and SN measurements.

LVD is a large volume detector which will be installed in Hall A of the Gran Sasso Laboratory. This detector is 49 m long, 13.2 m high and 12 m wide. It contains 2280 m3 of scintillator (1800 t) and 1800 t of steel. The geometric acceptance of LVD for an isotropic flux of particles is greater than 7000 m2 sr. LVD is the ideal detector for detecting a stellar collapse, anywhere in our galaxy; for studying neutrino oscillations; for searching for the supersymmetric decay mode of the proton; and for looking at the boron neutrinos from the sun. LVD is a very competitive detector for detecting astrophysical neutrino emitting point sources, for performing dark matter searches, for studying single muon distributions, for detecting muon bundles and hence determining the primary cosmic ray composition, and for searching for massive monopoles and other ultra heavy particles. LVD is composed of 190 identical modules, of which the first 10% of these modules will installed in 1987.

Using a high statistics sample of photo-produced charm particles from the FOCUS experiment at Fermilab, we report results of a search for eight rare and Standard-Model-forbidden decays: D+, Ds+ > h+/- muon-/+ muon+ (with h=pion or Kaon). Improvement over previous results by a factor of 1.7--14 is realized. Our branching ratio upper limit D+ > pion+ muon- muon+ of 8.8E-6 at the 90% C.L. is below the current MSSM R-Parity violating constraint.

Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement for the Cabibbo-suppressed decay mode D0→K+K−π+π−. We measure: Γ(D0→K+K−π+π−)/Γ(D0→K−π−π+π+)=0.0295±0.0011±0.0008. An amplitude analysis has been performed in order to determine the resonant substructure of this decay mode. The dominant components are the decays D0→K1(1270)+K−, D0→K1(1400)+K− and D0→ρ(770)0ϕ(1020).

Using a high statistics sample of photo-produced charm particles from the FOCUS experiment at Fermilab, we report on the measurement of the ratio of semileptonic rates \Gamma(D+ > ANTI-K pi mu+ nu)/\Gamma(D+ > ANTI-K0 mu+ nu)= 0.625 +/- 0.045 +/- 0.034. Allowing for the K pi S-wave interference measured previously by FOCUS, we extract the vector to pseudoscalar ratio \Gamma(D+ > ANTI-K*0 mu+ nu)/\Gamma(D+ > ANTI-K0 mu+ nu)= 0.594 +/- 0.043 +/- 0.033 and the ratio \Gamma(D+ > ANTI-K0 mu+ nu)/\Gamma(D+ > K- pi+ pi+)= 1.019 +/- 0.076 +/- 0.065. Our results show a lower ratio for \Gamma(D > K* \ell nu})/\Gamma(D > K \ell nu) than has been reported recently and indicate the current world average branching fractions for the decays D+ >ANTI-K0(mu+, e+) nu are low. Using the PDG world average for B(D+ > K- pi+ pi+) we extract B(D+ > ANIT-K0 mu+ nu)=(9.27 +/- 0.69 +/- 0.59 +/- 0.61)%.

We present a search for a charmed pentaquark decaying strongly to D(∗)−p. Finding no evidence for such a state, we set limits on the cross-section times branching ratio relative to D∗− and D− under particular assumptions about the production mechanism.

After briefly recapitulating the history of the charm quantum number we sketch the experimental environments and instruments employed to study the behaviour of charm hadrons and then describe the theoretical tools for treating charm dynamics. We discuss a wide range of inclusive production processes before analyzing the spectroscopy of hadrons with hidden and open charm and the weak lifetimes of charm mesons and baryons. Then we address leptonic, exclusive semileptonic and nonleptonic charm decays. Finally we treat $D^0 - \bar D^0$ oscillations and CP (and CPT) violation before concluding with some comments on charm and the quark-gluon plasma. We will make the case that future studies of charm dynamics -- in particular of CP violation -- can reveal the presence of New Physics. The experimental sensitivity has only recently reached a level where this could reasonably happen, yet only as the result of dedicated efforts. This review is meant to be both a pedagogical introduction for the young scholar and a useful reference for the experienced researcher. We aim for a self-contained description of the fundamental features while providing a guide through the literature for more technical issues.

Using a large sample of D+ -> K- pi+ mu+ nu decays collected by the FOCUS photoproduction experiment at Fermilab, we present the first measurements of the helicity basis form factors free from the assumption of spectroscopic pole dominance. We also present the first information on the form factor that controls the s-wave interference discussed in a previous paper by the FOCUS collaboration. We find reasonable agreement with the usual assumption of spectroscopic pole dominance and measured form factor ratios.

We present a search for a pentaquark decaying strongly to pKS0 in γN collisions at a center-of-mass energy up to 25 GeV. Finding no evidence for such a state in the mass range of 1470MeV/c2 to 2200MeV/c2, we set limits on the yield and on the cross section times branching ratio relative to Σ∗(1385)± and K∗(892)+.

In this paper we describe the testing of a prototype of an innovative displacement gauge, based on use of Fibre Bragg Grating (FBG) sensors. This displacement gauge, originally intended for monitoring repositioning of pixel vertex detectors in the BTeV experiment, is now proposed for CMS pixel alignment.

Theories involving curved momentum space, which recently became a topic of interest in the quantum-gravity literature, can, in general, violate many apparently robust aspects of our current description of the laws of physics, including relativistic invariance, locality, causality, and global momentum conservation. Here, we explore some aspects of the pathologies arising in generic theories involving curved momentum space for what concerns causality and momentum conservation. However, we also report results suggesting that when momentum space is maximally symmetric, and the theory is formulated relativistically, most notably including translational invariance with the associated relativity of spacetime locality, momentum is globally conserved and there is no violation of causality.

Resistive Plate Chambers have been chosen as dedicated trigger muon detector for the Compact Muon Solenoid experiment [1] at the Large Hadron Collider [2] at CERN. The system consists of about 3000 m2 of double gap RPC chambers placed in both the barrel and endcap muon regions.

The high-luminosity phase of the Large Hadron Collider (HL-LHC) will result in ten times higher particle background than measured during the first phase of LHC operation. In order to fully exploit the highly-demanding operating conditions during HL-LHC, the Compact Muon Solenoid (CMS) Collaboration will use Gas Electron Multiplier (GEM) detector technology. The technology will be integrated into the innermost region of the forward muon spectrometer of CMS as an additional muon station called GE1∕1. The primary purpose of this auxiliary station is to help in muon reconstruction and to control level-1 muon trigger rates in the pseudo-rapidity region 1.6≤|η|≤2.2. The new station will contain trapezoidal-shaped GEM detectors called GE1∕1 chambers. The design of these chambers is finalized, and the installation is in progress during the Long Shutdown phase two (LS-2) that started in 2019. Several full-size prototypes were built and operated successfully in various test beams at CERN. We describe performance measurements such as gain, efficiency, and time resolution of these prototype chambers, developed after years of R&D, and summarize their behavior in different gas compositions as a function of the applied voltage.

The CYGNO project aims at the development of a high precision optical readout gaseous Tima Projection Chamber (TPC) for directional dark matter (DM) searches, to be hosted at Laboratori Nazionali del Gran Sasso (LNGS). CYGNO employs a He:CF4 gas mixture at atmospheric pressure with a Gas Electron Multiplier (GEM) based amplification structure coupled to an optical readout comprised of sCMOS cameras and photomultiplier tubes (PMTs). This experimental setup allows to achieve 3D tracking and background rejection down to O(1) keV energy, to boost sensitivity to low WIMP masses. The characteristics of the optical readout approach in terms of the light yield will be illustrated along with the particle identification properties. The project timeline foresees, in the next 2–3 years, the realisation and installation of a 0.4 m3 TPC in the underground laboratories at LNGS to act as a demonstrator. Finally, the studies of the expected DM sensitivities of the CYGNO demonstrator will be presented.

Abstract We are going to discuss the R&amp;D and the prospects for the CYGNO project, towards the development of an innovative, high precision 3D tracking Time Projection Chamber with optical readout using He:CF 4 gas at 1 bar. CYGNO uses a stack of triple thin GEMs for charge multiplication, this induces scintillation in CF 4 gas, which is readout by PMTs and sCMOS cameras. High granularity and low readout noise of sCMOS along with high sampling of PMT allows CYGNO to have 3D tracking with head tail capability and particle identification down to O(keV) energy for directional Dark Matter searches and solar neutrino spectroscopy. We will present the most recent R&amp;D results from the CYGNO project, and in particular the overground commissioning of the largest prototype developed so far, LIME with a 33×33 cm 2 readout plane and 50 cm of drift length, for a total of 50 litres active volume. We will illustrate the LIME response characterisation between 3.7 keV and 44 keV by means of multiple X-ray sources, and the data Monte-Carlo comparison of simulated sCMOS images in this energy range. Furthermore, we will present current LIME installation, operation and data taking at underground Laboratori Nazionali del Gran Sasso (LNGS), serving as demonstrator for the development of a 0.4 m 3 CYGNO detector. We will conclude by mentioning the technical choices and the prospects of the 0.4 m 3 detector, as laid out in the Technical Design Report (TDR) recently produced by our collaboration.

Abstract The nature of dark matter is still unknown and an experimental program to look for dark matter particles in our Galaxy should extend its sensitivity to light particles in the GeV mass range and exploit the directional information of the DM particle motion (Vahsen et al. in CYGNUS: feasibility of a nuclear recoil observatory with directional sensitivity to dark matter and neutrinos, arXiv:2008.12587 , 2020). The Cygno project is studying a gaseous time projection chamber operated at atmospheric pressure with a Gas Electron Multiplier (Sauli in Nucl Instrum Meth A 386:531, https://doi.org/10.1016/S0168-9002(96)01172-2 , 1997) amplification and with an optical readout as a promising technology for light dark matter and directional searches. In this paper we describe the operation of a 50 l prototype named LIME (Long Imaging ModulE) in an overground location at Laboratori Nazionali di Frascati (LNF) of INFN. This prototype employs the technology under study for the 1 cubic meter Cygno demonstrator to be installed at the Laboratori Nazionali del Gran Sasso (LNGS) (Amaro et al. in Instruments 2022, 6(1), https://www.mdpi.com/2410-390X/6/1/6 , 2022). We report the characterization of LIME with photon sources in the energy range from few keV to several tens of keV to understand the performance of the energy reconstruction of the emitted electron. We achieved a low energy threshold of few keV and an energy resolution over the whole energy range of 10–20%, while operating the detector for several weeks continuously with very high operational efficiency. The energy spectrum of the reconstructed electrons is then reported and will be the basis to identify radio-contaminants of the LIME materials to be removed for future Cygno detectors.