Supernova Muons: New Constraints on Z' Bosons, Axions, and ALPs

TL;DR

This paper uses supernova neutrino observations to set new constraints on light particles like Z' bosons and axions that interact with muons, expanding the scope of particle physics models tested by astrophysical data.

Contribution

It provides the first constraints on Z' bosons coupled to muons and extends axion-muon coupling bounds over a wide mass range, including loop-level interactions.

Findings

Constrained Z' bosons with masses up to 250-500 MeV and couplings down to 10^{-9}.

Bound muon-coupled axions across masses from very low to 200-500 MeV.

Demonstrated supernovae as sensitive probes of new particles interacting with muons.

Abstract

New light particles produced in supernovae can lead to additional energy loss and a consequent deficit in neutrino production in conflict with the neutrinos observed from Supernova 1987A (SN1987A). Contrary to the majority of previous SN1987A studies, we examine the impact of $Z'$ bosons, axions, and axion-like particles (ALPs) interacting with the muons produced in SN1987A. For the first time, we find constraints on generic $Z'$ bosons coupled to muons, and apply our results to particle models including gauged $L_\mu-L_\tau$ number, $U(1)_{L_\mu-L_\tau}$, and gauged $B-L$ number, $U(1)_{B-L}$. We constrain $Z'$ bosons with masses up to about 250-500 MeV, and down to about $10^{-9}$ in $Z'$-muon coupling. We also extend previous work on axion-muon couplings by examining the importance of loop-level interactions, as well as performing calculations over a wider range of axion masses. We constrain muon-coupled axions from arbitrarily low masses up to about 200-500 MeV, with bounds extending down to axion-muon couplings of approximately $10^{-8}$ GeV$^{-1}$. We conclude that supernovae broadly provide a sensitive probe of new lightly-coupled particles interacting with muons.