Abstract 摘要 |
The inadequacy of perturbative QCD and lattice methods for estimating quark dynamics in quark gluon plasma(QGP) at finite temperature motivates many researchers to compute QGP observables(transport coefficients, drag force etc.) using gauge/gravity duality. Within the framework of gauge/gravity duality, the drag force experienced by an external heavy quark moving in N = 4 super Yang-Mills plasma at finite temperature was computed. In the dual gravity theory, an external heavy quark is modeled by a fundamental string attached to the boundary of an AdS-Schwarzschild black hole and extends along the radial direction. This external quark, with a mass proportional to the length of the string, loses its energy as the string trails back imparting a drag force. In our work we compute drag force on an external heavy probe quark moving in the presence of uniformly distributed heavy, static quark cloud on top of N = 4 SYM plasma at finite temperature. The dynamics of a heavy quark passing through the plasma is usually described by considering its interaction with the medium. In such calculations, any possible effects of other heavy quark due to the back-reaction of the plasma are neglected. In the context of N = 4 SYM, our work serves as an attempt to compute such back-reaction effects. Within the gauge/gravity correspondence, such effects can be modeled in terms of the deformation of the geometry due to finite density string cloud. This work shows that the back-reacted gravity background is explicitly computable. It turns out that the drag force enhances as the density of heavy quark cloud and temperature of the plasma rise up. |