Weak rates in strongly coupled cold quark matter

TL;DR

This paper derives a formula for weak process rates in cold quark matter at nonzero temperature, using a holographic model, revealing suppression compared to perturbative results, with implications for neutron star physics.

Contribution

It introduces a holographic approach to compute weak rates in strongly coupled quark matter, providing analytic and numerical results that extend beyond perturbative methods.

Findings

Weak rates are suppressed by logarithmic factors of temperature.

The derived formula is exact in QCD coupling and valid at high densities.

Numerical results match analytic approximations for small temperature deviations.

Abstract

The rates of flavor-changing weak processes are crucial in determining the conditions of beta equilibrium in neutron stars and mergers, influencing the damping of oscillations, the stability of rotating pulsars, and the emission of gravitational waves. We derive a formula for these rates at nonzero temperature, to leading order in the Fermi coupling and exact in the QCD coupling. Utilizing a simple phenomenological holographic model dual to QCD, we study massless unpaired quark matter at high densities. We numerically compute the rate for small deviations from beta equilibrium and derive an analytic approximation for small temperatures. Our findings reveal that, compared to the perturbative result, the rate is suppressed by logarithmic factors of the temperature.