Study of K * (892) 0 and f (1020) meson production in proton–proton and Pb–Pb collisions at ffiffiffiffiffiffiffiffiffi s NN p =2.76 TeV Y Ali 1 , M Ahmed 1 , A Arif 1 , Q Ali 1 , U Tabassam 1 , U Rubab 1 and M Suleymanov 1,2 1 Department of Physics, COMSATS University, Park Road, Islamabad, 44000, Pakistan 2 Institute for Physical Problems, Baku State University, Baku, AZ 1000, Azerbaijan E-mail: yasir_ali@comsats.edu.pk Received 11 September 2020, revised 3 December 2020 Accepted for publication 6 December 2020 Published 28 January 2021 Abstract In this paper, we describe a study of charged particle yield as a function of p T for K * (892) 0 and f (1020) mesons in proton–proton (pp) and Pb–Pb collisions at s NN =2.76 TeV in the central rapidity region of |y|<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 s NN =2.76 TeV. It was concluded that the models’ predictions for the f-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 f-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 f-mesons. Keywords: Quark Gluon Plasma, EPOS-LHC, nuclear modification factor (Some figures may appear in colour only in the online journal) Introduction The measurement of f-mesons and K *0 provides us with an insight into Quark Gluon Plasma (QGP), which is a hot and dense state of matter produced right after the big bang. In the lab environment, QGP is created at Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) by heavy ion collisions at low baryonic densities and high relativistic energies ranging from 200 GeV to 14 TeV [1–3]. These systems produces evolution through different stages, which show a transition from the deconfined state of QGP to a confined hadron state. Quantum Chromodynamics (QCD), which is the theory of strong interactions, helps to predict the degrees of freedom of quarks and gluons. The properties of this dense medium can be characterized by the energy loss of quarks and gluons traveling through a color-charged medium © 2021 Institute of Theoretical Physics CAS, Chinese Physical Society and IOP Publishing Printed in China and the UK Communications in Theoretical Physics Commun. Theor. Phys. 73 (2021) 025202 (7pp) https://doi.org/10.1088/1572-9494/abd0e7 0253-6102/21/025202+07$33.00 iopscience.org/ctp | ctp.itp.ac.cn 1