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Charged-particle multiplicity distributions over a wide pseudorapidity range in p-Pb collisions at TeV
No full textThis paper presents the primary charged-particle multiplicity distributions in proton--lead collisions at a centre-of-mass energy per nucleon--nucleon collision of TeV. The distributions are reported for non-single diffractive collisions in different pseudorapidity ranges. The measurements are performed using the combined information from the Silicon Pixel Detector and the Forward Multiplicity Detector of ALICE. The multiplicity distributions are parametrised with a double negative binomial distribution function which provides satisfactory descriptions of the distributions for all the studied pseudorapidity intervals. The data are compared to models and analysed quantitatively, evaluating the first four moments (mean, standard deviation, skewness, and kurtosis). The shape evolution of the measured multiplicity distributions is studied in terms of KNO variables and it is found that none of the considered models reproduces the measurements. This paper also reports on the average charged-particle multiplicity, normalised by the average number of participating nucleon pairs, as a function of the collision energy. The multiplicity results are then compared to measurements made in proton--proton and nucleus--nucleus collisions across a wide range of collision energies
Constraints on the equation of state of nuclear matter from systematically comparing SMASH calculations to HADES data
No full textDirect-photon production in inelastic and high-multiplicity proton–proton collisions at = 13 TeV
No full textIn this letter, we present the first measurement of direct photons at the transverse momentum of 1 < < GeV/ c at midrapidity |η| < 0.8 in inelastic and high-multiplicity proton–proton collisions at a centre-of-mass energy of = 13 TeV. The fraction of virtual direct photons in the inclusive virtual photon spectrum is obtained from a fit to the dielectron invariant mass spectrum. In the limit of zero invariant mass, this fraction is equal to the relative contribution of real direct photons in the inclusive real photon spectrum. Contributions from decays of light-flavour neutral mesons are estimated using independent measurements in proton–proton collisions at the same energy and the same event class. For the first time at the LHC energies, a direct-photon signal is observed at low in both inelastic and high-multiplicity event classes, with a significance of 3.2σ and 1.9σ in terms of standard deviations, correspondingly. The yield of direct photons in inelastic pp collisions is compared to perturbative QCD calculations. The integrated photon yield is studied as a function of charged-particle multiplicity and is compared to the results from other experiments and theoretical calculations. The results show a significant increase of direct-photon yield with charged-particle multiplicity
Direct-photon production in inelastic and high-multiplicity proton-proton collisions at 13 TeV
No full textMeasurement of (1285) production in pp collisions at = 13 TeV
No full textThis study presents the first measurement of the (1285) resonance using the ALICE detector in inelastic proton–proton collisions at a center-of-mass energy of 13 TeV. The resonance is reconstructed at midrapidity (|y|< 0.5) through the hadronic decay channel (1285) → . Key measurements include the determination of its mass, transverse-momentum integrated yield, and average transverse momentum. Additionally, the ratio of the transverse-momentum integrated yield of (1285) to pion is compared with calculations from the canonical statistical hadronization model. The model calculation, assuming a zero total strangeness content for (1285), reproduces the data within 1σ deviation, shedding light on the quark composition of (1285)
Performance study and gas system development for large-size GEM modules in the CBM-MuCh detector system
No full textMinimal material, maximum coverage: Silicon Tracking System for high-occupancy conditions
No full textSilicon strip sensors have long been a reliable technology for particle detection. Here, we push the limits of silicon tracking detectors by targeting an unprecedentedly low material budget of 2%–7% X0 in an 8-layer 4 m2 detector designed for high-occupancy environments (≤ 10 MHz/cm2). To achieve this, we employ Double-Sided Double Metal (DSDM) silicon microstrip sensors, coupled with readout electronics capable of precise timing and energy measurements. These 320μm thick sensors, featuring 2 × 1024 channels with a 58μm pitch, are connected via ultra-lightweight aluminum-polyimide microcables for signal transmission and integrated with a custom SMX readout ASIC, operating in free-streaming mode. This system enables the simultaneous measurement of time (Δt≃5ns) and charge deposition (0.1–100 fC), significantly enhancing the detector’s capacity for high-precision track reconstruction in high-occupancy and harsh radiation field environments. The primary application of this technology is the Silicon Tracking System (STS) for the CBM experiment, with additional potential in projects like the J-PARC E16 experiment and future uses in medical physics, such as advanced imaging telescopes. In this contribution, we present the current status of CBM STS construction, with almost one-third of the modules produced and tested. We also discuss immediate applications and explore promising prospects in both scientific and medical fields
