Gluon dissociation ofJ/ψin anisotropic quark-gluon plasma

Abstract

We calculate the gluon dissociation cross-section in an anisotropic quark gluon plasma expected to be formed in relativistic nucleus-nucleus collisions. It is shown that the thermally weighted cross-section of gluon dissociation undergoes modification in anisotropic plasma affecting the J/ψ survival probability. The dependence of the cross section on the direction of propagation of the charmonium with respect to the anisotropy axis is presented. Survival probability of J/ψ in two different space time models of anisotropic quark gluon plasma (AQGP) has been calculated. It is shown that depending upon the initial conditions (corresponding to RHIC energies), the survival probability in AQGP differs from that in isotropic QGP both in the central as well as forward rapidity regions. For initial conditions relevant for LHC energies, marginal difference between the the two space time models has been observed with a given initial conditions.

Some Aspects of Anisotropic Quark-Gluon Plasma

“…For higher , a similar feature has been observed in Figure 4(b), where the cross-section starts to increase beyond hard ∼ 200 MeV. For fixed hard , the dissociation cross-section as a function of shows that the cross-section first decreases and then marginally increases [15].…”

“…The dilepton production from quarkantiquark annihilation can be calculated from kinetic theory and is given by Figure 1: (Color online) Time evolutions of (a) the anisotropy parameter and (b) the hard momentum scale hard in the two space-time models described in the text. The graphs are taken from [15]. where ( ) is the phase space distribution function of the medium quarks (anti-quarks), V is the relative velocity between quark and anti-quark, and…”

“…We assume that the phase-space distribution for the anisotropic plasma is given by (6). Using the ansatz for the phase space distribution given in (6), one can simplify (15) to…”

“…A gluon with a four momentum = ( 0 , k) in the rest frame of the parton gas has energy 0 = ⋅ in the rest frame of the / . The thermal gluon / dissociation cross-section in anisotropic media is defined as [15,58]…”

“…where V rel = 1 − (k ⋅ P)/( 0 cosh ) is the relative velocity between / and the gluon. Now changing the variable ( ↔ ), one can obtain by using Lorentz transformation [15], the following relations:…”