Neutron star cooling with lepton-flavor-violating axions

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Zhang, Hong-Yi, Hagimoto, Ray, Long, Andrew J.
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866929329072504832
author Zhang, Hong-Yi
Hagimoto, Ray
Long, Andrew J.
author_facet Zhang, Hong-Yi
Hagimoto, Ray
Long, Andrew J.
contents The cores of dense stars are a powerful laboratory for studying feebly coupled particles such as axions. Some of the strongest constraints on axionlike particles and their couplings to ordinary matter derive from considerations of stellar axion emission. In this work we study the radiation of axionlike particles from degenerate neutron star matter via a lepton-flavor-violating coupling that leads to muon-electron conversion when an axion is emitted. We calculate the axion emission rate per unit volume (emissivity) and by comparing with the rate of neutrino emission, we infer upper limits on the lepton-flavor-violating coupling that are at the level of $|g_{aeμ}| \lesssim 10^{-6}$. For the hotter environment of a supernova, such as SN 1987A, the axion emission rate is enhanced and the limit is stronger, at the level of $|g_{aeμ}| \lesssim 10^{-11}$, competitive with laboratory limits. Interestingly, our derivation of the axion emissivity reveals that axion emission via the lepton-flavor-violating coupling is suppressed relative to the familiar lepton-flavor-preserving channels by the square of the plasma temperature to muon mass ratio, which is responsible for the relatively weaker limits.
format Preprint
id arxiv_https___arxiv_org_abs_2309_03889
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Neutron star cooling with lepton-flavor-violating axions
Zhang, Hong-Yi
Hagimoto, Ray
Long, Andrew J.
High Energy Physics - Phenomenology
High Energy Astrophysical Phenomena
The cores of dense stars are a powerful laboratory for studying feebly coupled particles such as axions. Some of the strongest constraints on axionlike particles and their couplings to ordinary matter derive from considerations of stellar axion emission. In this work we study the radiation of axionlike particles from degenerate neutron star matter via a lepton-flavor-violating coupling that leads to muon-electron conversion when an axion is emitted. We calculate the axion emission rate per unit volume (emissivity) and by comparing with the rate of neutrino emission, we infer upper limits on the lepton-flavor-violating coupling that are at the level of $|g_{aeμ}| \lesssim 10^{-6}$. For the hotter environment of a supernova, such as SN 1987A, the axion emission rate is enhanced and the limit is stronger, at the level of $|g_{aeμ}| \lesssim 10^{-11}$, competitive with laboratory limits. Interestingly, our derivation of the axion emissivity reveals that axion emission via the lepton-flavor-violating coupling is suppressed relative to the familiar lepton-flavor-preserving channels by the square of the plasma temperature to muon mass ratio, which is responsible for the relatively weaker limits.
title Neutron star cooling with lepton-flavor-violating axions
topic High Energy Physics - Phenomenology
High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2309.03889