Elliptic flow parameter in Au+Au and p+Au collisions at top RHIC energy

Dai-Mei Zhou,Yun Cheng,Yu-Liang Yan,Ben-Hao Sa,Xu Cai,Bao-Guo Dong

doi:10.1142/s2010194514602142

Abstract

The new issue of parton and hadron cascade model PACIAE 2.1 is utilized investigating the charged particle elliptic flow parameter v2 in Au + Au and p+ Au collisions at top RHIC energy. If the transverse momenta px and py of particles from string fragmentation are randomly sampled on the circumference of an ellipse instead of circle originally the PHENIX charged particle v2(η) and v2(pT) data in the 20-40% and 40-50% central Au + Au collisions at [Formula: see text] are fairly reproduced by the PACIAE 2.1 calculations, respectively. In addition, the charged particle v2(η) and v2(pT) in the p+ Au collisions at [Formula: see text] are predicted. It turned out that the charged particle elliptic flow parameter v2 may reach a measurable value of ~0.04 in the above p+ Au collisions.

Highlights

Four international collaborations of BRAHMS, PHOBOS, STAR, and PHENIX at RHIC have published white papers[1,2,3,4] to declare their evidences for the discovery of sfltorwonpgalyracmouetpelredofqpuraordku-gcleudonpaprltaicsmleain(sAQuG+PA)uaccoolluispiloenyseaatrs√asgNoN
Because in the PYTHIA model[15] ( PACIAE 2.0 model16) the transverse momentum px and py of produced particle in string fragmentation are randomly arranged on the circle with radius of pT, the final hadronic state transverse momentum asymmetry developed from the initial spatial asymmetry and the partonic rescattering is strongly reduced
In the PACIAE model simulations, the model parameters are all fixed as the same as default values given in PYTHIA, except the K factor, β, and Δt

Summary

Introduction

Four international collaborations of BRAHMS, PHOBOS, STAR, and PHENIX at RHIC have published white papers[1,2,3,4] to declare their evidences for the discovery of sfltorwonpgalyracmouetpelredofqpuraordku-gcleudonpaprltaicsmleain(sAQuG+PA)uaccoolluispiloenyseaatrs√asgNoN. This is an Open Access article published by World Scientific Publishing Company. It is hard to measure the particle elliptic flow parameter v2 experimentally. The conventional transport (cascade) models are always hard to reproduce the v2 experimental data in the nucleus-nucleus collisions at RHIC (LHC) energies. The default AMPT model (AMPT def ) underestimated the v2 experimental data in the nucleus-nucleus collisions at RHIC energies.[13] they have to update AMPT def to the AMPT with string melting (AMPT sm). Because in the PYTHIA model[15] ( PACIAE 2.0 model16) the transverse momentum px and py of produced particle in string fragmentation are randomly arranged on the circle with radius of pT , the final hadronic state transverse momentum asymmetry developed from the initial spatial asymmetry and the partonic rescattering is strongly reduced. The v2 experimental data is able to be described

Models

Results and Discussions

Conclusions