Studying Effects of Evolution on Charge Separation in Small Collision System with A MultiPhase Transport model

Abstract

In relativistic high energy heavy-ion collisions, Chiral Magnetic Effect (CME) could produce a charge separation in QGP. The charge separation could survive into final hadron system during evolution, observed as correlator $Δγ$. This physics procedure could also occurs in small collision system if CME emerge in the QGP droplet. In this paper, we study the effects of QGP droplet evolution on charge separation in small collision system, based on AMPT model. Our calculation indicates that, with given initial charge separation, the effects of parton level evolution and hadron level evolution weaken the charge separation indeed, but there is still enough signals could remained. Furthermore, we found that, the contribution of background to $Δγ$ is negligible in small collision system. So, we propose the small collision system being a good place to confirm contribution of CME.