Study Of K*(892)(0) And Phi (1020) Meson Production In Proton-Proton And Pb-Pb Collisions At Root S(Nn)=2.76 Tev

In this paper, we describe a study of charged particle yield as a function of p(T) for K*(892)(0) and phi (1020) mesons in proton-proton (pp) and Pb-Pb collisions at root s(NN) = 2.76 TeV in the central rapidity region of vertical bar y vertical bar < 0.5, in a p(T) range of 0 < p(T) < 15 GeV c(-1) in pp collisions and in a p(T) range of 0 < p(T) < 20 GeV c(-1) in Pb-Pb collisions. We also investigated a very important ratio, the nuclear modification factor, to study the effects of the medium in the most central region, i.e. 0%-5% centrality. For data simulation, we used the EPOS-LHC and EPOS-1.99 models. To check the validity of these models' simulations, we compared the data obtained from these Monte Carlo simulation programs with ALICE experimental data for root s(NN) = 2.76 TeV. It was concluded that the models' predictions for the phi-meson in pp and for the most central Pb-Pb collisions disagreed with the ALICE data, and that the difference increased with p(T). This may be connected with the essential role of collective parton behaviors which could not have been taken into account by the models. For K*(0) mesons, both programs gave almost the same predictions, and with p(T) in the interval p(T) > 3 GeV c(-1), the predictions were very close to the experimental data. Both models gave higher predictions for the soft p(T) interval and lower predictions for the hard interactions. The values of the R-AA distributions were lower than unity and both models were very close to the ALICE data. It is very interesting that the models were not able to describe the p(T) distributions, but they gave good predictions for their ratios. This may possibly be due to parton collective behaviors. We observed some additional suppression of K*(0) at low values of p(T) with respect to phi-mesons, which may be related to the role of the masses of the particles in soft interactions. The rising trend for R-AA in the region from p(T) = 10 GeV c(-1) to 20 GeV c(-1) observed by the ALICE experiment was absent for the phi-mesons.