Multimessenger search for electrophilic feebly interacting particles from supernovae

TL;DR

This paper investigates MeV-scale electrophilic feebly interacting particles produced in supernovae, analyzing their potential signatures in photon and cosmic-ray data to constrain their interactions with electrons.

Contribution

It introduces a model-independent framework for analyzing FIP-induced leptonic signals from supernovae across multiple messengers, combining theoretical predictions with experimental data.

Findings

Constraints on FIP-electron interactions from multimessenger data

Identification of potential signatures in gamma-ray and cosmic-ray observations

A comprehensive analysis applicable to various FIP models

Abstract

We study MeV-scale electrophilic Feebly Interacting Particles (FIPs), that may be abundantly produced in Supernova (SN) explosions, escape the star and decay into electrons and positrons. This exotic injection of leptons in the Milky Way leaves an imprint in both photon and cosmic-ray fluxes. Specifically, positrons lose energy and annihilate almost at rest with background electrons, producing photons with $511$ keV energy. In addition, electrons and positrons radiate photons through bremsstrahlung emission and upscatter the low-energy galactic photon fields via the inverse Compton process generating a broad emission from X-ray to $\gamma$-ray energies. Finally, electrons and positrons are directly observable in cosmic ray experiments. In order to describe the FIP-induced lepton injection in full generality, we use a model independent parametrization which can be applied to a host of FIPs such as axion-like particles, dark photons and sterile neutrinos. Theoretical predictions are compared to experimental data to robustly constrain FIP-electron interactions with an innovative multimessenger analysis.