Centrality dependence of limiting fragmentation

We investigate the centrality-dependent validity of the limiting-fragmentation hypothesis in relativistic heavy-ion collisions at energies reached at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). A phenomenological analysis of Au–Au and Pb–Pb collisions within a three-source relativistic diffusion model (RDM) is performed at $$\sqrt{s_{NN}}=19.6, 62.4, 130, 200, 2760$$ s NN = 19.6 , 62.4 , 130 , 200 , 2760 and 5023 GeV using four centrality cuts at each energy. Linear and nonlinear expressions for the rapidity drift function are tested and their physical relevance is discussed. Our results are compatible with the limiting-fragmentation conjecture for the investigated centralities in the full energy range. The number of particles in the fragmentation and fireball sources are found to depend on $$\sqrt{s_{NN}}$$ s NN logarithmically and cubic-logarithmically, respectively.

Diffusion-model analysis of pPb and PbPb collisions at LHC energies

We present an analysis of centrality-dependent pseudorapidity distributions of produced charged hadrons in pPb and PbPb collisions at the Large Hadron Collider (LHC) energy of [Formula: see text] = 5.02 TeV, and of minimum-bias pPb collisions at 8.16 TeV within the non-equilibrium-statistical relativistic diffusion model (RDM). In a three-source approach, the role of the fragmentation sources is emphasized. Together with the Jacobian transformation from rapidity to pseudorapidity and the limiting fragmentation conjecture, these are essential for modeling the centrality dependence. For central PbPb collisions, a prediction at the projected FCC energy of [Formula: see text] = 39 TeV is made.

TRANSVERSE MOMENTUM DISTRIBUTION WITH RADIAL FLOW IN RELATIVISTIC DIFFUSION MODEL

Large transverse momentum distributions of identified particles observed at the Relativistic Heavy Ion Collider (RHIC) are analyzed by a relativistic stochastic model in the three dimensional (non-Euclidean) rapidity space. A distribution function obtained from the model is Gaussian-like in radial rapidity. It can well describe observed transverse momentum pT distributions. Estimation of radial flow is made from the analysis of pT distributions for [Formula: see text] in Au + Au Collisions. Temperatures are estimated from observed large pT distributions under the assumption that the distribution function approaches to the Maxwell–Boltzmann distribution in the lower momentum limit. The power-law behavior of large pT distribution is also derived from the model.