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Strongly interacting matter at extremely high net-baryon density has drawn a renewed interest, and high-energy heavy ion collision experiments are being performed worldwide to study such a matter. The high net-baryon densities produced in energetic heavy ion collisions are similar to those in the core of a neutron star, although the temperature is high. The equation of state and other properties of such a medium sheds light on the nature of the medium including the formation of a deconfined state of quarks and gluons called quark–gluon plasma (QGP). One such upcoming dedicated high-density experiment at FAIR-Germany called compressed baryonic matter (CBM) will be discussed in detail.

The Compressed Baryonic Matter experiment (CBM) will study rare probes in a heavy-ion environment at high interaction rates of up to 10 MHz. The observation of detached vertices requires a topological trigger, which is too complex to be defined in the hardware, and fully realized in software. Excluding conventional, latency-limited trigger architectures, CBM opted for a free-running readout. The primary beam is delivered by a slow extraction synchrotron. To be able to operate the experiment at highest interaction rates, despite beam intensity fluctuations, a time-based throttling mechanism is under study. SystemVerilog based simulations of the readout system show the feasibility of the examined throttling algorithm to reduce the number of incomplete events, particularly in presence of intensity fluctuations.

The detector modules of the Silicon Tracking System of the Compressed Baryonic Matter experiment at FAIR comprise double-sided silicon microstrip sensors with a size of up to 124 mm x 62 mm. Due to tight material budget constraints, the sensors are connected to the read-out electronics by long flexible microcables. As manual assembly of the modules is time-consuming and difficult, a fully customized in-house bonder machine has been developed which allows for a highly automated detector module assembly. We present the requirements and the setup of the bonder machine together with the achieved alignment accuracy and first assemblies.

The Compressed Baryonic Matter (CBM) experiment has decided to use the Multi-gap Resistive Plate Chambers(MRPC) technology to build its Time-Of-Flight (TOF) wall. CBM-TOF requires a rate capability over 20 kHz/cm2 for inner region. A 10-gap pad-MRPC assembled with low resistive glass is designed to construct this area. The prototypes, which consist of 10×0.22 mm gas gaps and 2×8 20 mm×20 mm readout pads, require fewer electronic channels compared to the strip design. A timing resolution of around 60 ps and an efficiency above 98% were obtained in a cosmic test and a beam test taken in 2014 October GSI beam time. The results show that the real-size prototypes fulfill the requirements of the CBM-TOF.

Particles 3(2), 320 - 335 (2020). doi:10.3390/particles3020024, The future “Facility for Antiproton and Ion Research” (FAIR) is an accelerator-based international center for fundamental and applied research, which presently is under construction in Darmstadt, Germany. An important part of the program is devoted to questions related to astrophysics, including the origin of elements in the universe and the properties of strongly interacting matter under extreme conditions, which are relevant for our understanding of the structure of neutron stars and the dynamics of supernova explosions and neutron star mergers. The Compressed Baryonic Matter (CBM) experiment at FAIR is designed to measure promising observables in high-energy heavy-ion collisions, which are expected to be sensitive to the high-density equation-of-state (EOS) of nuclear matter and to new phases of Quantum Chromo Dynamics (QCD) matter at high densities. The CBM physics program, the relevant observables and the experimental setup will be discussed., Published by MDPI AG, Basel

The evolution of matter created in a heavy-ion collision depends on its initial geometry. Experimentally collision geometry is characterized with centrality. Procedure of centrality determination for the Compressed Baryonic Matter (CBM) experiment at FAIR is presented. Relation between parameters of the collision geometry (such as impact parameter magnitude) and centrality classes is extracted using multiplicity of produced charged particles. The latter is connected to the collision geometry parameters using Monte-Carlo Glauber approach.

The silicon sensors of the Silicon Tracking System of the Compressed Baryonic Matter experiment at FAIR, GSI are connected to the read-out electronics by low mass flexible microcables due to tight material budget restrictions. The cable length of up to 50 cm and its flexible nature make detector module assembly one of the most critical parts in STS. A novel low mass, low capacitance multilayer copper microcable has been designed and produced to facilitate detector assembly. Furthermore, a novel detector production method based on high-density gold stud bump bonding of silicon die on microcable has been developed. We present the Cu microcable design, capacitance simulations and measurements together with the individual steps performed in the STS detector assembly.

The scientific goal of the CBM (Compressed Baryonic Matter) experiment at FAIR (Darmstadt) is to explore the phase diagram of strongly interacting matter at highest baryon densities. The physics program of the CBM experiment is complimentary to the programs to be realized at MPD and BMN facilities at NICA and will start with beam derived by the SIS100 synchrotron. The results of JINR participation in the development of different sub-projects of the CBM experiment are presented.

The Compressed Baryonic Matter experiment (CBM) operating at high heavy-ion interaction rates of up to 10 MHz excludes conventional, latency-limited trigger architectures. Instead, CBM opted for a trigger-less streaming readout. To be able to operate the experiment at highest interaction rates, despite beam intensity fluctuations introduced by the slow extraction of the SIS 100 synchrotron, a time-based throttling mechanism is investigated. To achieve a high number of complete readout events, different throttling strategies are compared and the throttling algorithms and parameters are optimized.

Qualitative and quantitative similarities as a function of the system size in heavy ion collisions from low energy dissipative collisions, collective expansion of compressed baryonic matter up to the geometrical scaling evidenced at the highest energies presently attainable at LHC, are presented., 6 pages, 5 figures Lecture presented at CARPATHIAN SUMMER SCHOOL OF PHYSICS 2018 Exotic Nuclei and Nuclear / Particle Astrophysics (VII)

The Compressed Baryonic Matter (CBM) experiment is one of four major scientific pillars at the future Facility for Antiproton and Ion Research (FAIR). It aims to study the properties of nuclear matter at high net-baryon densities and moderate temperatures. It is expected that, utilizing ultra-relativistic heavy-ion collisions, a phase transition from hadronic matter to QCD matter will be probed. To measure and determine the physics phenomena occurring in these collisions, appropriate detectors are required.

As the civil works for the SIS100 accelerator have started at FAIR/GSI and the design of the Compressed Baryonic Matter (CBM) experiment and its detector subsystems have progressed to an almost complete level, also the production of most of the detectors and components is starting soon. Commissioning of larger test systems (“FAIR Phase 0”) and last detector characterisations are being conducted. In this paper, the design of the MWPC-based Transition Radiation Detector (TRD) for the very high particle rates of the CBM experiment is shown. We present details of the self-triggered front-end electronics of the TRD and general aspects of the read-out. Furthermore, results on the energy resolution of the TRD and first insights into recent measurements of TRD-MWPCs in the high-rate field of the CERN Gamma Irradiation Facility are presented.

Due to the expected irradiation damage at the Silicon Tracking System (STS) of the Compressed Baryonic Matter (CBM) experiment at FAIR, bi-phase CO2 will be used for cooling ∼ 40 kW of heat dissipated by electronics. For the efficient thermal performance of the electronics, several measurements aimed at improving the thermal interfaces and simulations for extracting the operational parameters of the CO2 cooling are presented. These efforts are towards building a cooling demonstrator with first two STS half-stations to show that the CBM-STS cooling concepts are viable.

Prototypes of the gas-filled detectors produced on the basis of the Micromegas technology, as well as in combination with the Micromegas + GEM/TGEM structures in the multistage gas amplification circuit have been investigated with the aim of selecting variants for tracking detectors of the muon system designed for operating at high counting rates in the Compressed Baryonic Matter (CBM) experiment. Two- and three-component Ar- and He-based mixtures have been tested as the working gas. Their key characteristics are presented. The gas amplification factors are measured for various high-voltage modes, and the charge collection times determining the response speed of the tested detectors are estimated.

The Compressed Baryonic Matter (CBM) experimental setup is currently being constructed at the Facility for Antiproton and Ion Research (FAIR) acceleration complex in GSI (Darmstadt, Germany) by an international collaboration that includes a team from JINR. One of the primary goals of this experiment is to study charmonium production in high-energy nuclear collisions. It is meant to track down decays such as J/ψ → μ+μ− in the online mode. The present paper gives criteria for the effective selection of signal events by using exclusively data on charged muons collected in Muon Chamber (MUCH) coordinate stations.

The Compressed Baryonic Matter (CBM) experiment at the upcoming Facility for Antiproton and Ion Research (FAIR) will explore the phase diagram of nuclear matter at very high net-baryon densities and moderate temperatures in nucleus–nucleus collisions at beam energies up to 45 A GeV . One of the key diagnostic probes is electromagnetic radiation. In order to minimize systematic errors of this challenging measurement, CBM aims at an investigation of dielectron and dimuon pairs in the full mass range from the photon point up to charmonium. The results of performance studies for dilepton measurements and the status of the detector developments are presented.

The charged particle trajectory online reconstruction in the Compressed Baryonic Matter (CBM) experiment (GSI, Germany) is an extremely difficult task. It is conditioned by a high rate of the ion beam-tar-get collisions (up to 107/s), high track multiplicity in each nucleus-nucleus collision (up to 1000 particles), and charged-particle trajectory registration with the coordinate detectors located in a highly inhomogeneous magnetic field. Such a problem could be solved only by using modern high-performance computers. This work scrutinizes a Kalman filter based track reconstruction algorithm implemented using different parallelization approaches. To perform the analysis, a many-core hybrid server with two Intel Xeon X5660 CPUs and a NVidia GTX 480 GPU (JINR LIT) was used.

The structure and results of the experimental study of the application specific integrated circuit, which contains two versions of a preamplifier for reading out and preprocessing signals of muon chambers, are presented. An integrated circuit was designed for operation in the muon system of the International Compressed Baryonic Matter (CBM) experiment at the FAIR accelerator facility (Darmstadt, Germany). It was manufactured by the CMOS technology with 0.18-μm design rules of the UMC company (Taiwan) via the Europractice European organization.

A clustering problem for the coordinate detectors in the Compressed Baryonic Matter (CBM) experiment is discussed. Because of the high interaction rate and huge datasets to be dealt with, clustering algorithms are required to be fast and efficient and capable of processing events with high track multiplicity. At present there are two different approaches to the problem. In the first one each fired pad bears information about its charge, while in the second one a pad can or cannot be fired, thus rendering the separation of overlapping clusters a difficult task. To deal with the latter, two different clustering algorithms were developed, integrated into the CBMROOT software environment, and tested with various types of simulated events. Both of them are found to be highly efficient and accurate.

The Compressed Baryonic Matter (CBM) experiment at the Facility for Antiproton and Ion Research (FAIR) at Darmstadt will be a dedicated heavy-ion experiment for the investigation of baryonic matter at highest net-baryon densities. A RICH detector with CO2 as radiator gas is being developed for clean and efficient electron identification which will be necessary for the measurement of some of the key observables of the physics program of CBM. The status of the development of this RICH detector and results on R&D activities concerning self-triggered readout electronics for PMTs, studies on the usage of wavelength-shifting films, as well as the evaluation of glass mirrors from industrial providers will be presented.

A new project NICA/MPD ( N uclotron-based I on C ollider f A cility/ M ulti P urpose D etector) is under active development now at JINR (Dubna). The main goal of the project is to start in the coming years an experimental study of hot and dense strongly interacting matter and search for possible signs of the mixed phase and critical endpoint in heavy ion collisions. This study should be carried out at center-of-mass ion collision energies of s N N = 4 ÷ 11 GeV (nucleon-nucleon equivalent) and an average luminosity of L = 10 27 cm − 2 s − 1 for Au (79+). Another goal of the project is aimed at the study of spin physics with colliding beams of polarized protons and deuterons. The SPD (Spin Physics Detector) setup will be designed and built for that purpose. This report contains the physics motivation and main characteristics of the facility, the scheme and operation scenario for heavy ion collision mode and the current concept of the MPD setup. Status and plans of the project realization schedule are presented as well.

Di-electron spectroscopy is considered to be one of the major programs of the Compressed Baryonic Matter (CBM) experiment at the future FAIR accelerator at Darmstadt. In this contribution, the analysis strategy for the reconstruction of low-mass vector mesons with the proposed CBM detector setup is discussed. Results from feasibility studies will be presented and compared with data from existing dilepton experiments.

In this paper, we present a systematic investigation of an optimization of the di-electron setup of the CBM experiment for the measurement of low-mass vector mesons, and establish a limit on pion misidentification.

Measurements of the directed and elliptic flow of strange and multi-strange hadrons are an important part of the physics program of the Compressed Baryonic Matter experiment (CBM) at the future accelerator complex FAIR in Darmstadt, Germany. We present recent results from the CBM performance studies for measurements of the directed (

The High Acceptance Di-Electron Spectrometer (HADES) is operational since the year 2000 and uses a hadron blind RICH detector for electron identification. The RICH photon detector is currently replaced by Hamamatsu H12700 MAPMTs with a readout system based on the DiRICH front-end module. The electronic readout chain is being developed as a joint effort of the HADES-, CBM- and PANDA collaborations and will also be used in the photon detectors for the upcoming Compressed Baryonic Matter (CBM) and PANDA experiments at FAIR . This article gives a brief overview on the photomultipliers and their quality assurance test measurements, as well as first measurements of the new DiRICH front-end module in final configurations.

The Compressed Baryonic Matter (CBM) experiment will be one of the major scientific activities at the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt. The goal of the CBM research program is to explore the QCD phase diagram in the region of high baryon densities using high-energy nucleus–nucleus collisions. This approach is complementary to the heavy-ion research program at RHIC and LHC where QCD matter at very high temperatures is studied. The relevant observables and the layout of the proposed CBM experimental facility will be discussed.

We have studied the possibility to detect vector mesons via their decay into μ+μ− pairs in heavy-ion collisions at FAIR with a muon detection system as part of the Compressed Baryonic Matter (CBM) experiment.

Doses and fluences in the experimental hall and equipment are calculated for the CBM project of the future accelarator Facility for Antiproton and Ion Research in Darmstadt. The calculations are based on the FLUKA code adapted to the CBMROOT framework.

FAIR, the future Facility for Anti-proton and Ion Research at Darmstadt, shall provide heavy ion and antiproton beams of unprecedented intensities, with several of the core experiments to investigate the physics of strong interactions. With the planned high interaction rates of up to 2 · 107 s−1 using cooled antiprotons of 1.5–15 GeV/c, the PANDA detector will allow high-precision measurements and the observation of rare reaction channels.

The Compressed Baryonic Matter (CBM) experiment at the future Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt will be a dedicated heavy-ion experiment exploring the QCD phase diagram in the region of moderate temperatures but very high baryon densities. The currently foreseen CBM detector setup, physics observables of interest, and first feasibility studies of their measurement will be presented.

The investigation of nuclear matter at extreme conditions, that is, at high temperatures and/or at high baryon densities, is one of the most challenging fields of modern physics. Worldwide, major efforts are devoted to the exploration of the phase diagram of strongly interacting matter using high energy nucleus-nucleus collisions. While the experiments at the Relativistic Heavy Ion Collider (RHIC) at BNL and at the future Large Hadron Collider (LHC) at CERN focus on the study of high temperatures, the Compressed Baryonic Matter (CBM) experiment at the future FAIR accelerator will concentrate on the investigation of highest baryon densities at still moderate temperatures.

The elastic neural net is implemented for finding rings in Cherenkov detector. The method does not require any prior track information and can be used for triggering. Application of the method to the RICH detector of the CBM experiment [CBM Collaboration, Compressed baryonic matter experiment, Technical Status Report, GSI, Darmstadt, 2005] shows very good efficiency and extremely high speed.

At the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt a dedicated heavy-ion experiment investigating the properties of highly compressed baryonic matter (CBM) is proposed. Its goal will be to explore the QCD phase diagram in the region of moderate temperatures but very high baryon densities. Physics observables of interest, the experimental challenge of measuring them and first feasibility studies on charm production will be discussed.

At the future Facility for Antiproton and Ion Research in Darmstadt (FAIR) a dedicated heavy-ion experiment investigating the properties of highly Compressed Baryonic Matter is proposed (CBM). A key observable of the physics program will be a precise measurement of low-mass vector mesons in their leptonic decay channel. The essential experimental tool for identifying the decay electrons will be a gaseous RICH detector. The concept of this RICH detector will be introduced and discussed.

A major field of research at the future accelerator facility at GSI will be the exploration of the QCD phase diagram in the region of high baryon densities. Experimental observables and the proposed detector system will be discussed.