V. Palichik

NICA-Nuclotron (Nuclotron-based Ion Collider fAility) is a new accelerator complex being constructed at the Joint Institute for Nuclear Research (Dubna, Russia) to study properties of dense baryonic matter. BM@N (Baryonic Matter at Nuclotron) is the first fixed target experiment at the NICA-Nuclotron facility. The aim of the experiment is to study collisions of relativistic ion beams of the kinetic energy from 1 to 4.5 AGeV with fixed targets. BM@N energies are perfectly suitable for strange hypernuclei investigation. This year BM@N started a new physics program aiming at studying the Short Range Correlations (SRC). SRC are brief fluctuations of two nucleons with high and opposite momenta, where each of them is higher than the Fermi momentum for the given nucleus, and the center of mass momentum is close to zero. The presence of SRC pairs within nuclei and their properties have important implications for nuclear physics, high energy physics, and astrophysics. The BM@N setup uses a carbon beam hitting a liquid hydrogen target, which makes it possible to detect the residual nucleus after hard knock-out of the two SRC nucleons. We present an overview of the main detection systems used for the SRC measurement as well as the first results from the tracking detectors.

The BM@N experiment is considered as the first phase of NICA Mega science project. The energy of the beam will vary from 1 to 6 GeV/u. The beams delivered by Nuclotron will be of different types from protons to Au. The ability to reconstruct the beam momentum with high precision is one way for showing that the tracking detectors are tuned in the right way and the reconstruction procedure performs well. A quick overview of the experimental setup is given in the work along with the description of some of the main tracking detectors. The beam momentum reconstruction procedure is described and results are presented for different values of the beam energy.

The Baryonic Matter at Nuclotron (BM@N) experiment represents the first phase of the Nuclotron-based Ion Collider Facility (NICA), a mega-science project at the Joint Institute for Nuclear Research. It is a fixed target experiment built for studying nuclear matter in conditions of extreme density and temperature. The tracking system of the BM@N experiment consists of three main detector systems: Multiwire Proportional Chambers situated before the magnet, Gas Electron Multipliers placed inside the magnet and Drift Chambers placed after the magnet. These systems provide the reconstruction of charged particles’ trajectories and their momentum in the magnetic field. This information is further used by Time of Flight detectors for the particle identification procedure. The system’s performance is reviewed and the spatial resolutions along with efficiencies of the detectors are estimated using the data collected in the recent physics runs of the Nuclotron.

A new segment building algorithm for the Cathode Strip Chambers in the CMS experiment is presented. A detailed description of the new algorithm is given along with a comparison with the algorithm used in the CMS software. The new segment builder was tested with different Monte-Carlo data samples. The new algorithm is meant to be robust and effective for hard muons and the higher luminosity that is expected in the future at the LHC.

A robust technique with a sub-optimal weight function (M-estimate) was applied to investigate track fitting in cathode strip chambers (CSCs) and determine the CSC spatial resolution. The comparative analysis with the conventional least squares method was made on simulated data and experimental data from the Dubna CSC prototype. The results obtained definitely prove a necessity of using robust track fitting for a reliable estimation of muon chamber spatial resolution.

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The algorithm for track reconstruction in multiwire proportional chambers (MWPCs) of the BM@N (Baryonic Matter at Nuclotron) experiment is described. The beam tracks before the interaction with the target and trajectories of charged particles after the interaction are reconstructed using Nuclotron experimental data with deuteron and carbon beams colliding with the carbon and copper targets. Trajectories are extrapolated to the interaction point and to drift chambers. The efficiencies of MWPCs have been obtained. Beam parameters (transverse dimensions and angular spread) have been measured as well.

BM@N (Baryonic Matter at Nuclotron) is the first experiment at the accelerator complex of NICA-Nuclotron at JINR (Dubna). The aim of the experiment is to study collisions of relativistic ion beams of the kinetic energy from 1 to 4.5 AGeV with fixed targets. The last run started a new physics program of BM@N – Short Range Correlations (SRC) studies in light nuclei. The BM@N setup allows detecting of the residual nucleus for the first time. BM@N tracking detectors play a key role in the identification of the nucleus after hard scattering in inverse kinematics. We present the first results of the BM@N tracking detectors using the data collected in spring 2018.

Nowadays grid technologies are the key to success for large-scale projects. LHC accelerator with its physical installations is one of the directions where the distributed infrastructure for data processing comes in hand. In this paper an overview of the grid infrastructure at JINR is given. Some statistics is brought up along with case studies of successful usage of grid technologies by institute's science groups.

The aim of this work is to estimate the shower leakage from the CMS Endcap Hadron calorimeter (HE) due to electromagnetic secondaries and punch-through in the region of the ME1/1 Forward Muon Station. Two configurations are considered: with and without the CMS Endcap Electromagnetic calorimeter (EE). The experimental data have been taken during the combined beam test of CMS subdetectors (HE, ME, RPC, DT) at the CERN H2 beam facility in 2004. Serial CSC chambers (ready for installation in CMS) fully equipped with readout electronics have been exposed. Simulation of a beam test setup has been performed using the GEANT4-based simulation software package OSCAR.

The Baryonic Matter at Nuclotron (BM@N) is the first experiment with a fixed target at the Nuclotron-based Ion Collider fAcility (NICA) in Dubna (Russia). Along with baryonic matter study, the BM@N physics program includes the study of Short-Range Correlations (SRC) in nuclei. The SRC measurement was carried out in 2018. We used 12C beam with the momentum of 48 GeV/c and a liquid hydrogen target. The quasi-free scattering of 12C on protons was recorded with the BM@N spectrometer, which was slightly modified for the SRC experiment. Particularly, the target proton and knocked out proton under the condition of scattering at 90 degrees in the center-of-mass coordinate system were recorded in the arm spectrometer using time-of-flight and coordinate detectors. After interaction, the residual nucleus continued moving along the beam and passed through the scintillator and coordinate detectors as well as the analyzing magnet. This contribution describes the track reconstruction in Multiwire Proportional Chambers (MWPC) and Silicon Detector systems (Si), as well as a method of obtaining combined tracks after the target using the information from MWPC and Si. This is a basis for the identification of nuclear fragments described in the first physics analysis, which was submitted for publication.

The Gas Electron Multiplier (GEM) chambers are developed for modern purposes in the elementary particle physics. In the BM@N experiment, a GEM system is used for the reconstruction of the trajectories of the charged particles. The investigation of GEM performance (efficiency and spatial resolution) is presented.

The Large Hadron Collider is delivering a growing luminosity and rate of interactions. This imposes strict requirements on the algorithms used for the reconstruction of charged particle trajectories. We present the results of the improvements achieved in the local reconstruction algorithms used in the cathode strip chambers of the CMS experiment.

Extended gauge models and the Randall-Sundrum model with extra-dimension predict the existence of TeV-mass resonances. The LHC potential for a five sigma level discovery was investigated as described in this document. Final states containing large invariant mass di-muons from ${Z}^{\prime}$ and the RS1 graviton were studied. The possibility of discriminating between different ${Z}^{\prime}$ model by measuring the muon forward-backward asymmetry was investigated. The determination of the spin of the resonance is also discussed.

Extended gauge models and the Randall-Sundrum model with extra-dimension predict the existence of TeV-mass resonances. The LHC potential for a five sigma level discovery was investigated as described in this document. Final states containing large invariant mass di-muons from ${Z}^{\prime}$ and the RS1 graviton were studied. The possibility of discriminating between different ${Z}^{\prime}$ model by measuring the muon forward-backward asymmetry was investigated. The determination of the spin of the resonance is also discussed.