摘要
We study the centrality dependence of the mid-rapidity （｜y｜ 〈 0.5） yields and transverse momentum distributions of K＊ （892）° and φ（1020） resonances produced in Pb ＋ Pb collisions at SNN= 2.76 TeV. The mid- rapidity 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.
基金
Supported by Council of Scientific and Industrial Research,New Delhi for This Work
