Centrality Dependence of ${{\boldsymbol{K}}}^{* }{(892)}^{0}$ and ϕ (1020) Production at LHC

Abstract

We study the centrality dependence of the mid-rapidity (|y| < 0.5) yields and transverse momentum distributions of K * (892) 0 and ϕ(1020) resonances produced in Pb + Pb collisions at √ sNN = 2.76 TeV. The midrapidity density (dN/dy) and the shape of the transverse momentum spectra are well reproduced by an earlier proposed Unified Statistical Thermal Freeze-out Model (USTFM), which incorporates the effects of both longitudinal as well as transverse hydrodynamic flow. The freeze-out properties in terms of kinetic freeze-out temperature and transverse flow velocity parameter are extracted from the model fits to the transverse momentum data provided by the ALICE experiment at the LHC. The kinetic freeze-out temperature is found to increase with decreasing event centrality while the transverse flow velocity parameter shows a mild decrease on moving towards peripheral collisions. Moreover the centrality dependence of the mid-rapidity system size at freeze-out has also been studied in terms of transverse radius parameter.

Effects of Coalescence and Isospin Symmetry on the Freezeout of Light Nuclei and Their Anti-particles

“…However, the collisions become less violent as the centrality decreases and less number of participants involve in the interactions which results in comparatively low kinetic freezeout temperature. This is in agreement with[11][12][13][14][15][16], but in disagreement with[17][18][19][20].…”

“…However, the situation for kinetic freezeout temperature is not clear. several literatures claim larger T 0 in central collisions [11][12][13][14][15][16] which decrease towards periphery, while several claims larger T 0 in peripheral collisions [17][18][19][20] which decrease towards the central collisions. In addition, volume is also very important parameter in high energy collisions.…”