Contribution of the thermal mass to the chiral vortical effect and magnetobaryogenesis

TL;DR

This paper demonstrates that the chiral vortical effect can occur in a nonchiral electroweak plasma at thermal equilibrium, influencing hypermagnetic field generation and matter-antimatter asymmetry in the early Universe.

Contribution

It introduces a nonperturbative formula for the vortical current considering thermal masses, revealing how gauge and Yukawa interactions affect the effect.

Findings

Thermal masses induce T^2 corrections to the vortical current.

Gauge interactions' contributions cancel out due to gauge symmetry.

Yukawa interactions' contributions do not cancel, enabling the effect.

Abstract

We show that the chiral vortical effect can exist in a nonchiral electroweak plasma in thermal equilibrium using the effective thermal masses of the fermions in the symmetric phase. We use a nonperturbative formula for the vortical current, which has been recently obtained and is a functional of the dispersion relation. Then, taking into account the effect of fermion thermal mass in the dispersion relation, we show that the corresponding hyperelectric vortical current receives implicit thermal corrections proportional to T2, from both the gauge and Yukawa interactions of the fermion. We show that the contributions of gauge interactions to the thermal masses in the total hyperelectric vortical current cancel out due to the gauge symmetries, while those of the Yukawa interactions do not cancel out. We finally show that, due to this current, only small transient vorticity fluctuations about the zero background value in a nonchiral electroweak plasma in thermal equilibrium can activate the chiral vortical effect, leading to the generation of hypermagnetic fields and matter-antimatter asymmetries in the symmetric phase of the early Universe, in the temperature range 100GeV<T<10TeV, all starting from zero initial values, even in the presence of the weak sphaleron processes.