June COST WG3 Meeting

Friday 27 Jun 2025, 15:00 → 16:00 Europe/Rome

Marina Cermeño Gavilán will present the talk 

Title: New probes of supernova axion-like particles in neutrino water Cherenkov detectors

June WG3 Meeting 
Friday, June 27 · 15:00 – 16:00
Time zone: Europe/Madrid
Google Meet joining info
Video call link: https://meet.google.com/jnh-csmw-tvs

Abstract: In this talk I will present a new potential signature of supernova axion-like particles (ALPs)  in neutrino water Cherenkov detectors. If ALPs couple to protons, then they can be detected through ALP absorption on free protons, ap→pγ, where the resulting photon has approximately the energy of the ALP. This new signature is complementary to the previously proposed from oxygen de-excitation, and can be exploited in various ways. 
I will first argue that ALPs with MeV masses produced in core-collapse SNe will travel with semi-relativistic velocities and can constitute a nearly constant flux formed by the overlap of ALP fluxes from past galactic supernovae. Using SuperKamiokande data, new constraints on the ALP-proton coupling can be derived in an unexplored region of the parameter space. For lighter ALPs, the conditions for a nearly constant flux are not satisfied. However, these particles may still be detectable in a future nearby supernova. I will show that this new signature, combined with the one expected from oxygen de-excitation, would allow us to disentangle ALP-neutron and ALP-proton couplings