An Explanation for Heavy Quark Energy Loss Puzzle by Flow Effects

TL;DR

This paper explains the heavy quark energy loss puzzle by incorporating flow effects in a dynamic medium, revealing modifications to the dead cone and LPM effects that increase energy loss and lead to similar suppression for light and heavy quarks in heavy-ion collisions.

Contribution

It introduces a novel explanation for the heavy quark energy loss puzzle by considering collective flow effects, showing how they alter gluon emission processes and dead cone structures.

Findings

Flow effects induce two dead cones in gluon emission.

Energy loss differences among charm, bottom, and light quarks are minimal.

Similar high pT suppression for light and heavy quarks in central collisions.

Abstract

The heavy quark energy loss puzzle is explained by collective flow effects in a dynamic medium. The dead cone and LPM effect are found to be changed comparing to the static medium case. Instead of only one dead cone in the static medium, the collective flow induces two dead cones from two different kinds of processes. One is from the projectile emitting gluon process, the same as that in the static medium. The other is from the gluon emission off the exchanged gluon process, decreasing with increasing flow velocity $v_z$ along jet direction, which lead to the increase of heavy quark energy loss. The differences of the effective average energy loss among charm, bottom and light quarks are very little from a full 3D ideal hydrodynamic simulation for 0-10$%$ central Au-Au collisions at RHIC energy. This would yield similar high $p_{T}$ suppressions between light and heavy quarks for central Au-Au collisions.