arXiv subjects

CBM Collaboration

Publications and source records attributed to CBM Collaboration.

4 recordsLinked to original sources

arXiv2026

CBM physics program and recent experimental developments

The Compressed Baryonic Matter (CBM) fixed-target experiment is under construction at the Facility for Antiproton and Ion Research. It aims to explore the phase structure of strong interaction (QCD) matter at high net-baryon densities and moderate temperatures using heavy-ion collisions in the center-of-mass energy range per nucleon pair $\sqrt{s_{\mathrm{NN}}} =$ 2.7--4.9\,GeV. Equipped with fast and radiation-hard detector systems and an advanced triggerless data acquisition scheme, CBM will collect data at interaction rates of up to 10 MHz by performing online reconstruction and event selection. This will facilitate measurements of rare probes not accessible so far in this energy range, including multi-strange hadron production and their flow coefficients, high-order net-baryon cumulants, dileptons, as well as production of double-strange hypernuclei. The CBM detector is outlined and selected physics performance results based on realistic simulations are discussed.

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arXiv2026

Demonstrating CBM Capabilities by $\Lambda$ Baryon Reconstruction in Ni+Ni Collisions with the mCBM Experiment at SIS18 of GSI/FAIR

The Compressed Baryonic Matter (CBM) experiment at the upcoming Facility for Antiproton and Ion Research (FAIR) is a high-rate fixed-target experiment designed to investigate nuclear matter at extreme baryon densities in relativistic nucleus-nucleus collisions. To enable high-statistics measurements of rare probes, CBM is designed to operate at event rates up to 10 MHz. This necessitates the development of fast and radiation-tolerant detectors, self-triggered front-end electronics, a free-streaming data acquisition architecture, and real-time event reconstruction capabilities. Prototype versions and pre-series productions of the CBM detector systems have been deployed in the mini-CBM demonstrator setup mCBM - an experimental precursor comprising sub-components of all major CBM systems, installed at the SIS18 facility of GSI/FAIR within the FAIR Phase-0 program. In 2024, Ni+Ni collisions at a kinetic beam energy of 1.93 AGeV and an average interaction rate of about 250 kHz were successfully recorded. This dataset enables a detailed evaluation of the operational performance of the detector systems as well as the complete CBM data chain, while the reconstruction of rare $\Lambda$ baryons serves as a natural benchmark. This paper presents the first results on $\Lambda$ signal reconstruction with the mCBM experiment, demonstrating the readiness of the detector technologies and the data chain for the upcoming full-scale CBM experiment.

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arXiv2024

Lightweight Thermal Management Strategies for the Silicon Detectors of CBM at FAIR

Lightweight thermal management is central to the design of the all-silicon Inner Tracker of the Compressed Baryonic Matter Experiment (CBM) at the Facility for Antiproton and Ion Research (FAIR). This experiment aims to study strongly interacting matter at neutron star core densities through fixed-target Au-Au collisions ($\sqrt{s_{NN}} = 2.9 - 4.9$\,GeV; up to 10$^7$ beam-target interactions per second; polar angular acceptance of $2.5^{\circ} \leq \Theta \leq 25^{\circ}$). Studies with thermal demonstrators for both the pixel-based Micro Vertex Detector and the strip-based Silicon Tracking System have validated their thermal management strategies, preparing them for series production now and global commissioning in 2028.

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arXiv2016

Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.

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