Chiral magnetic effect in the anisotropic quark-gluon plasma

Mohammad Ali-Akbari,Seyed Farid Taghavi

doi:10.1007/jhep04(2015)181

Abstract

An anisotropic thermal plasma phase of a strongly coupled gauge theory can be holographically modelled by an anisotropic AdS black hole. The temperature and anisotropy parameter of the AdS black hole background of interest [1] is specified by the location of the horizon and the value of the Dilaton field at the horizon. Interestingly, for the first time, we obtain two functions for the values of the horizon and Dilaton field in terms of the temperature and anisotropy parameter. Then by introducing a number of spinning probe D7-branes in the anisotropic background, we compute the value of the chiral magnetic effect (CME). We observe that in the isotropic and anisotropic plasma the value of the CME is equal for the massless quarks. However, at fixed temperature, raising the anisotropy in the system will increase the value of the CME for the massive quarks.

Highlights

Right-handed quarks, is proportional to the of non-trivial gauge field provided that the left-handed and right-handed quarks are initially equal
In order to shed some light on the dynamic of chiral magnetic effect (CME) in the early stages of heavy ion collision, we investigate the effect of simplified anisotropic environment, where the pressure in one direction of space is different from the other directions
We have studied the effects of the anisotropy parameter and the temperature on the CME

Summary

Review on the anisotropic background

The background we are interested in is an anisotropic solution of the IIb supergravity equations of motion [1]. This solution in the string frame is given by ds2 = gttdt2 + gxx(dx2 + dy2) + gzzdz2 + guudu2 + g55ds2S5 , ds2S5 = dθ2 + cos θds2S3 + sin θdψ, χ = az, φ = φ(u). Χ and φ are axion and dilaton fields respectively. In terms of the dilaton field, they have the following forms. Note that the solution contains a self dual five-form field(see appendix. An anisotropy is clearly seen between the transverse and longitudinal directions. The study of various properties of the above background has been done in the literature, e.g. see [25,26,27,28,29]