Effective Chiral Magnetic Effect from Neutrino Radiation

TL;DR

This paper develops a new theoretical framework for understanding an effective chiral magnetic effect induced by neutrino radiation in dense matter, with implications for supernovae and pulsar kicks.

Contribution

It introduces a systematic approach to chiral kinetic theory for electrons and neutrinos, deriving an effective CME without a chiral chemical potential, applicable to nonequilibrium dense matter.

Findings

Effective CME can be significantly enhanced by neutrino emission in supernovae.

The enhanced CME can drive inverse cascades of magnetic and kinetic energies.

The results suggest a possible explanation for pulsar kicks.

Abstract

We develop an approach to chiral kinetic theories for electrons close to equilibrium and neutrinos away from equilibrium based on a systematic power counting scheme for different timescales of electromagnetic and weak interactions. Under this framework, we derive electric and energy currents along magnetic fields induced by neutrino radiation in general nonequilibrium states. This may be regarded as an effective chiral magnetic effect (CME), which is present without a chiral chemical potential, unlike the conventional CME. We also consider the so-called gain region of core-collapse supernovae as an example and find that the effective CME enhanced by persistent neutrino emission in time is sufficiently large to lead to the inverse cascade of magnetic and fluid kinetic energies and observed magnitudes of pulsar kicks. Our framework may also be applicable to other dense-matter systems involving nonequilibrium neutrinos.