Scaling of anisotropic flow and momentum-space densities for light particles in intermediate energy heavy ion collisions

T.Z Yan,K Wang,J.G Chen,Y.G Ma,D.Q Fang,X.Z Cai,C.W Ma,W Guo,W.D Tian,E.J Ma,W.Q Shen

doi:10.1016/j.physletb.2006.05.018

Abstract

Abstract Anisotropic flows ( v 2 and v 4 ) of light nuclear clusters are studied by isospin-dependent quantum molecular dynamics model for the system of 86 Kr + 124 Sn at intermediate energy and large impact parameters. Number-of-nucleon scaling of the elliptic flow ( v 2 ) are demonstrated for the light fragments up to A = 4 , and the ratio of v 4 / v 2 2 shows a constant value of 1/2. In addition, the momentum-space densities of different clusters are also surveyed as functions of transverse momentum, in-plane transverse momentum and azimuth angle relative to the reaction plane. The results can be essentially described by momentum-space power law. All the above phenomena indicate that there exists a number-of-nucleon scaling for both anisotropic flow and momentum-space densities for light clusters, which can be understood by the coalescence mechanism in nucleonic degree of freedom for the cluster formation.

Highlights

The power law behaviors of light fragment production in momentum space are explored in our model simulation
Recent ultrarelativistic Au + Au collision experiments demonstrated the number of constituent-quark (NCQ) scaling from the transverse momentum dependent elliptic flow for the different mesons and baryons at the Relativistic Heavy Ion Collider (RHIC) in Brookhaven National Laboratory [11], it indicates that the partonic degree of the freedom plays a dominant role in formation
The range of transverse momentum for different fragments is different according to their masses. It shows that the elliptic flow is positive and it increases with the increasing pt. It reflects that the light clusters are preferentially emitted within the reaction plane, and particles with higher transverse momentum tend to be strongly emitted within in-plane, i.e. stronger positive elliptic flow

Summary

Introduction

The power law behaviors of light fragment production in momentum space are explored in our model simulation. Anisotropic flow is of interesting subject in theoretical and experimental investigations on nuclear reaction dynamics in intermediate and high energy heavy-ion collisions [1,2,3,4,5,6,7,8,9,10].

Results

Conclusion