Study Of Charge Asymmetry Dependence Of Elliptic Flow Of ?~± By AMPT Model

This paper first introduces the standard model of particle physics and the gen-eration of quark-gluon plasma(QGP),and then describes the process of relativistic heavy ion collision that can create a high temperature and high density environment to produce QGP,which gives rise to phenomena such as elliptic flow that reflecte the geometric information of initial state particles or possible local parity violation in QGP metastable states.Then,we introduce the theory of chiral magnetic effect and chiral magnetic wave,the recent research results of RHIC-STAR experiments,LHC-ALICE experi-ments and LHC-CMS experiments,and the theory of local charge conservation.The theory of chiral magnetic wave indicates that there exists a certain linear dependence between the asymmetric coefficients of charge and elliptic flow.On the one hand,the experimental results of RHIC-STAR and LHC-ALICE on the relationship between the asymmetric coefficients of charge and elliptic flow are consistent with the pre-diction of chiral magnetic wave theory,which justify the validity of chiral magnetic wave theory to some extent.On the other hand,LHC-CMS experimental results show that there is a similar linear dependence in both small systems and triangular flows,which may reject the chiral magnetic wave theory to some extent and justify the local charge conservation theory.In order to explore the relationship between elliptic flow and charge asymmetry,and other underlying physical mechanisms,we explored the relationship between meson elliptic flow and charge asymmetry based on AMPT model.In this study,we simulated Au+Au collision under 200GeV selected by AMPT model with string melting,and obtained 300,000 events with centrality of 30-40%.To ensure that the simulated events can satisfy the conservation of charge,we specifically shut down the hadronic cascade mechanism,which only retained the resonant decay in ART.This paper then studies the relation between the charge asymmetry coefficients and the elliptic flows of meson and antimeson produced from the original AMPT model as well as these produced from the decays of of A baryons and neutral p mesons.It was found that,for the originally produced mesons and antimesons in the AMPT model,the elliptic flow v2 has no obvious linear relation with Ach,in addition,?v2 and Ach also do not display linear dependences,the fitting slope is almost 0.The quantities v2 and Ach of the original mesons of ART also didn't show the linear dependence with a positive and a negative slope as in experiments.What is more,we studied the relationship between the average transverse momentum<p7>and Ach of particles and antiparticles.The result shows that(pT)tends to decrease slightly with the increase of Ach,but the amplitude is small,and the slope of the average transverse momentum difference<?pT>)and Ach is almost 0.For mesons and antimesons produced from the decay of A baryons,the two types of elliptical flows v2 show no obvious dependence on Ach,and the difference between the two elliptical flows ?v2 also has no linear dependence to Ach.However,for mesons and antimesons produced from the decays of neutral p mesons,we found that the elliptic flow of ?+ increases with respect to Ach while the elliptic flow of?-decreases with respect to Ach,and the difference between the two elliptical flows ?v2 is also negatively related to Ach,which are opposite to the experimental results.The study shows that,in our model,both for mesons and antimesons that pro-duced from the original AMPT model as well as these produced from the decays of ?baryons and neutral p mesons,the elliptic flows and the charge asymmetric coefficien-t failed to display a linear dependence in consistence with the experimental results.Under the current framework of AMPT model,we cannot explain the experimental results yet.Further exploration and research are needed to seek for the underlying physical mechanisms.