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Resonance suppression during the hadronic stage from the FAIR to the intermediate RHIC energy regime
No full textThe energy and centrality dependence of the kaon resonance ratio (K∗0 + ¯K∗0 )/(K+ + K− ) is explored inthe RHIC-BES and CBM-FAIR energy regime. To this aim, the ultrarelativistic quantum molecular dynamicsmodel is employed to simulate reconstructable K∗ resonances in Au + Au and p + p collisions from √s NN =3–39 GeV. We obtain a good description of the resonance yields and mean transverse momenta over the wholeinvestigated energy range. The decrease of the K∗/K ratio with increasing centrality is in line with the availableexperimental data. We also observe the experimenatlly measured increase in 〈pT〉 with increasing centralitywhich is interpreted as a lower reconstruction probability of low-pT K∗ due to the pT dependent absorption of thedecay daughter hadrons. We conclude that the observed suppression of reconstructable K∗ resonances providesa strong sign of an extended hadronic rescattering stage at all investigated energies. Its duration increases fromperipheral to central reactions as expected. Following a method, suggested by the STAR experiment, a lowerbound on the duration of the hadronic stage is extracted using the K∗/K ratios at chemical and kinetic freeze-out.The resulting lifetimes are in good agreement with the experimental data, but shorter than the actual lifetime ofthe hadronic phase in the transport simulations
Toward a foundation model for heavy-ion collision experiments based on point-cloud diffusion
No full textDetermination of the -meson production process and its absorption cross section via directed flow
No full textIt is shown that the directed flow of ϕ-mesons in Au+Au collisions at sNN=3 GeV, is sensitive to the production and the absorption cross section of the ϕ in a nuclear medium. This provides a new observable to constrain the in-medium properties of the ϕ which is independent of its absolute production rate. STAR data disfavor any significant ϕ-N absorption in dense nuclear matter and are consistent with a very small cross section of the ϕ comparable to the vacuum cross section. The similarity of the ϕ-meson and proton directed flow also indicates that the ϕ is produced in conjunction with a baryon
Production of double strange hypernuclei and exotic nuclei in central Au+Au collisions at = 3 GeV
No full textWe extend the theoretical approach which includes the dynamical and statistical stages for the description of the nucleosynthesis in central collisions of relativistic ions. Previously, this approach was successfully applied to describe experimental data on both normal nuclei and single strange hypernuclei production in the GSI and RHIC-BES energy range. We predict the multiplicities of double strange hypernuclei up to ΛΛ4ΛΛ4H and further intermediate mass nuclei up to 88Be for Au+Au central collisions at sNNsNN = 3 GeV, recently explored by the STAR experiments. These nuclei can be identified by the measurement of the correlated particles coming after their decay. Such observations are a crucial test for the nucleosynthesis mechanism
Particle production as a function of charged-particle flattenicity in pp collisions at = 13 TeV
No full textThis paper reports the first measurement of the transverse momentum spectra of primary charged pions, kaons, (anti)protons, and unidentified particles as a function of the charged-particle flattenicity in pp collisions at . Flattenicity is a novel event shape observable that is measured in the pseudorapidity intervals covered by the V0 detector, $2.
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