Neutrino production mechanisms in strongly magnetized quark matter: Current status and open questions

TL;DR

This paper reviews how strong magnetic fields affect neutrino emission mechanisms in dense quark matter within compact stars, highlighting anisotropic and oscillatory behaviors impacting star cooling and dynamics.

Contribution

It provides a comprehensive analysis of neutrino emission processes in magnetized quark matter, emphasizing Landau-level effects and their implications for astrophysical phenomena.

Findings

Neutrino emissivity becomes anisotropic and oscillatory with magnetic field strength.

Landau quantization significantly influences the direct Urca process in dense quark matter.

Magnetic field effects may impact magnetar cooling and pulsar kick mechanisms.

Abstract

We review the main neutrino emission mechanisms operating in dense quark matter under strong magnetic fields, with particular emphasis on conditions expected in the interiors of compact stars. We discuss the direct Urca and neutrino synchrotron processes in unpaired quark matter, incorporating the effects of Landau-level quantization. For the direct Urca process, the quantization of the electron energy spectrum plays a critical role, whereas quark quantization can often be neglected at sufficiently high baryon densities. The resulting field-dependent neutrino emissivity is anisotropic and exhibits an oscillatory behavior as a function of magnetic-field strength. We explore the implications of these effects for magnetar cooling and for possible anisotropic neutrino emission that could contribute to pulsar kicks. In addition, we review the $\nu\bar{\nu}$ synchrotron emission process, which, although subdominant, provides valuable insights into the interplay between magnetic fields and weak interactions in dense quark matter. Overall, our analysis highlights the nontrivial influence of strong magnetic fields on neutrino production in magnetized quark cores, with potential consequences for the thermal and dynamical evolution of compact stars.