On viscous flow and azimuthal anisotropy of quark-gluon plasma in strong magnetic field

TL;DR

This paper calculates the anisotropic viscous pressure tensor of quark-gluon plasma in strong magnetic fields, revealing significant azimuthal anisotropy that impacts the interpretation of shear viscosity measurements.

Contribution

It introduces a detailed calculation of the viscous pressure tensor in strong magnetic fields, highlighting the anisotropic shear viscosity coefficients and their effects on flow asymmetry.

Findings

Viscous pressure tensor is azimuthally anisotropic in strong magnetic fields.

Four of five shear viscosity coefficients vanish at high magnetic field strength.

Magnetic fields can cause flow asymmetries up to one-third, affecting shear viscosity estimates.

Abstract

We calculate the viscous pressure tensor of the quark-gluon plasma in strong magnetic field. It is azimuthally anisotropic and is characterized by five shear viscosity coefficients, four of which vanish when the field strength eB is much larger than the plasma temperature squared. We argue, that the azimuthally anisotropic viscous pressure tensor generates the transverse flow with asymmetry as large as 1/3, even not taking into account the collision geometry. We conclude, that the magnitude of the shear viscosity extracted from the experimental data ignoring the magnetic field must be underestimated.