# Rate of dark photon emission from electron positron annihilation in massive stars

## TL;DR

This paper calculates the production rate of dark photons from electron-positron annihilation in supernova-like environments, considering plasma effects and mixing, to understand their impact on massive star evolution.

## Contribution

It provides a detailed calculation of dark photon emission rates in dense stellar matter, including plasma effects and mode distinctions, for the 1-10 MeV mass range.

## Key findings

- Dark photon emission rates depend non-linearly on mass and plasma conditions.
- Plasma effects significantly influence the emission rate calculations.
- Implications for stellar evolution when dark photons decay into standard or dark sector particles.

## Abstract

We calculate the rate of production of dark photons from electron-positron pair annihilation in hot and dense matter characteristic of supernova progenitors. Given the non-linear dependence of the emission rate on the dark photon mass and current astrophysical constraints on the dark photon parameter space, we focus on the mass range of 1--10 MeV. For the conditions under consideration both mixing with the in-medium photon and plasma effects on the electron dispersion relation are non-negligible and are explored in detail. We perform our calculations to the leading order in the fine-structure constant. Transverse and longitudinal photon modes are treated separately given their different dispersion relations. We consider the implications for the evolution of massive stars when dark photons decay either into particles of the standard model or of the dark sector.