Magnetic field induced neutrino chiral transport near equilibrium

TL;DR

This paper develops a near-equilibrium chiral neutrino transport model in supernovae, revealing magnetic field-induced neutrino energy currents and their potential link to pulsar kicks.

Contribution

It introduces an analytic near-equilibrium solution for chiral neutrino transport incorporating magnetic field effects, derived from effective field theory.

Findings

Neutrino energy current is proportional to magnetic field.

Derived explicit expressions for nonequilibrium corrections.

Discussed implications for pulsar kicks.

Abstract

Based on the recently formulated chiral radiation transport theory for left-handed neutrinos, we study the chiral transport of neutrinos near thermal equilibrium in core-collapse supernovae. We first compute the near-equilibrium solution of the chiral radiation transport equation under the relaxation time approximation, where the relaxation time is directly derived from the effective field theory of the weak interaction. By using such a solution, we systematically derive analytic expressions for the nonequilibrium corrections of the neutrino energy-momentum tensor and neutrino number current induced by magnetic fields via the neutrino absorption on nucleons. In particular, we find the nonequilibrium neutrino energy current proportional to the magnetic field. We also discuss its phenomenological consequences such as the possible relation to pulsar kicks.