Wake in anisotropic quark-gluon plasma

Abstract

We calculate the wake in charge density and the wake potential due to the passage of a fast parton in an anisotropic quark-gluon plasma. For the sake of simplicity, a small $\ensuremath{\xi}$ (anisotropic parameter) limit has been considered. When the velocity ($v$) of the jet is parallel to the anisotropy direction ($\stackrel{^}{n}$) and remains below the phase velocity (${v}_{p}$), the wake in induced charge density shows a little oscillatory behavior in anisotropic quark-gluon plasma, contrary to the isotropic case. With the jet velocity greater than the phase velocity, the oscillatory behavior increases with $\ensuremath{\xi}$. Also for $v>{v}_{p}$ one observes a clear modification of the conelike structure in the presence of anisotropy. For the parallel direction in the backward region, the depth of the wake potential decreases with the increase of $\ensuremath{\xi}$ for $v<{v}_{p}$, and the potential becomes modified Coulomb-like for higher values of $\ensuremath{\xi}$. In the forward region, the potential remains modified Coulomb-like with the change in magnitude for nonzero $\ensuremath{\xi}$, for both $v>{v}_{p}$ and $v<{v}_{p}$. In the perpendicular direction, the wake potential is symmetric in the forward and backward regions. With the increase of $\ensuremath{\xi}$, the depth of negative minimum is moving away from the origin irrespective of the jet velocity. On the other hand, when the jet velocity is perpendicular to the anisotropy direction, we find significant changes in the case of both wake charge density and potential in comparison to the isotropic case. For nonzero $\ensuremath{\xi}$, the oscillatory nature of the color charge wake is reduced at $v>{v}_{p}$. Also the oscillatory behavior of the wake potential along the direction of motion of the parton is attenuated in the backward direction for anisotropic plasma at parton velocity $v>{v}_{p}$. In the presence of anisotropy, for $v<{v}_{p}$, the screening potential along the perpendicular direction of the parton is transformed from the Lennard-Jones type to a modified Coulomb-like potential.