Parton Scatter Effect On Collective Flow From AMPT Model

Since the 1980s,high-energy heavy ion collision physics has started to develop.With the increase of the coverage area of the Large Hadron Collider and the improvement of the detector performance,the exploration of high-energy physics is getting deeper.High-temperature and high-density nuclear materials can be formed in high-energy heavy ion collision experiments,which can be used to study quark gluon plasma and QCD phase diagrams.Due to the small spatial scale and short duration of the system,we can only understand the physical mechanism of the reaction process through the final state particles.Collective flow represents the anisotropic distribution of particles in momentum space,which is related to the initial state of the system and the evolution of dynamics.It is a good observable measure to study the asymmetry of the initial coordinate space to the asymmetry of the momentum space of the final state.The study of the collision process of high-energy heavy ions is mainly through the model.Among them,the AMPT model can give a good simulation of the experimental results of the RHIC energy region,and it adds parton cascade process to the previous transport model.QGP is simulated by partons,and the evolution of the system is mainly expressed by the scattering process between partons.When the energy density of the system decline to a certain level,the parton phases begin to transform into hadron phases through quark coalescence.This article mainly analyzes the 14.5GeV and 39 Ge V Au + Au collision based on the AMPT model,and also contains the results of the 200 Ge V studies for comparison.By analyzing the number of hadron component quark scattering,the influence of the scattering process on the collective flow is studied,which mainly focuses on the differential elliptic flow,integral elliptic flow,and dynamic conversion efficiency of initial shape to final state elliptic flow.The study found that large transverse momentum particles participated in fewer scattering times but larger elliptic flow,and the evolution process of all partons are basically the same,but after recombination selection,the component quarks of different hadrons experience different average scattering times and the component quarks that experience the same number of scattering have different contributions to the elliptic flow.In addition,the research also found that the anti-proton momentum spatial azimuth distribution does not conform to the cos2 x function image.The other hadrons also have similar phenomena.It is considered to be the result ofselection of particles in hadronization based on the result of parton interaction,which is related to partial distribution and hadron ratio.By changing the coalescence method,first binding baryon and then meson,this asymmetric phenomenon has been improved.