On the origin of mixed inhomogeneous phase in vortical gluon plasma

TL;DR

This paper investigates the inhomogeneous phase structure of vortical gluon plasma, revealing that a quadratic magnetovortical coupling primarily determines the phase's spatial configuration, supported by numerical and Monte Carlo simulations.

Contribution

It identifies the dominant role of the magnetovortical coupling in shaping the inhomogeneous phase of vortical gluon plasma, advancing understanding of its spatial properties.

Findings

The inhomogeneous phase is mainly governed by the magnetovortical coupling.

Linear coupling to angular momentum has a subleading effect.

Monte Carlo simulations support the magnetic coupling's role in phase structure.

Abstract

Recently, lattice simulations of SU(3) Yang-Mills theory revealed that rotating hot gluon matter in thermal equilibrium possesses a novel inhomogeneous phase consisting of the deconfinement phase located in the center region, which is spatially separated from the confinement phase in the periphery. This inhomogeneous two-phase structure is also expected to be produced by vorticity in quark-gluon plasma formed in non-central relativistic heavy-ion collisions. We show that its vortical properties are determined by two types of couplings of the angular velocity to the gluon fields: a linear coupling to the mechanical angular momentum of gluons and a quadratic ``magnetovortical'' coupling to a chromomagnetic component. We demonstrate numerically that the distinctive inhomogeneous structure of the vortical (quark-)gluon plasma is determined by the latter, while the former plays only a subleading role. We argue that the anisotropy of the gluonic action in the curved co-rotating background can quantitatively explain the remarkable property that the spatial structure of this inhomogeneous phase disobeys the picture based on a straightforward implementation of the Tolman-Ehrenfest law. We also support our findings with Monte Carlo simulations of Yang-Mills plasma at the real-valued angular frequency, which take into account only the magnetic part of the action.