Adiabatic Axion-Photon Mixing Near Neutron Stars

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Tjemsland, Jonas, McDonald, Jamie, Witte, Samuel J.
Format: Preprint
Veröffentlicht: 2023
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866909061472059392
author Tjemsland, Jonas
McDonald, Jamie
Witte, Samuel J.
author_facet Tjemsland, Jonas
McDonald, Jamie
Witte, Samuel J.
contents One of the promising new proposals to search for axions in astrophysical environments is to look for narrow radio lines produced from the resonant conversion of axion dark matter falling through the magnetospheres of neutron stars. For sufficiently strong magnetic fields, axion masses in the $\mathcal{O}(10μ{\rm eV)}$ range, and axion-photon couplings $g_{aγ} \gtrsim 10^{-12} \, {\rm GeV^{-1}}$, the conversion can become hyper-efficient, allowing axion-photon and photon-axion transitions to occur with $\mathcal{O}(1)$ probabilities. Despite the strong mixing between these particles, the observable radio flux emanating from the magnetosphere is expected to be heavily suppressed -- this is a consequence of the fact that photons sourced by infalling axions have a high probability of converting back into axions before escaping the magnetosphere. In this work, we study the evolution of the axion and photon phase space near the surface of highly magnetized neutron stars in the adiabatic regime, quantifying for the first time the properties of the radio flux that arise at high axion-photon couplings. We show that previous attempts to mimic the scaling in this regime have been overly conservative in their treatment, and that the suppression can be largely circumvented for radio observations targeting neutron star populations.
format Preprint
id arxiv_https___arxiv_org_abs_2310_18403
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Adiabatic Axion-Photon Mixing Near Neutron Stars
Tjemsland, Jonas
McDonald, Jamie
Witte, Samuel J.
High Energy Physics - Phenomenology
Cosmology and Nongalactic Astrophysics
High Energy Astrophysical Phenomena
One of the promising new proposals to search for axions in astrophysical environments is to look for narrow radio lines produced from the resonant conversion of axion dark matter falling through the magnetospheres of neutron stars. For sufficiently strong magnetic fields, axion masses in the $\mathcal{O}(10μ{\rm eV)}$ range, and axion-photon couplings $g_{aγ} \gtrsim 10^{-12} \, {\rm GeV^{-1}}$, the conversion can become hyper-efficient, allowing axion-photon and photon-axion transitions to occur with $\mathcal{O}(1)$ probabilities. Despite the strong mixing between these particles, the observable radio flux emanating from the magnetosphere is expected to be heavily suppressed -- this is a consequence of the fact that photons sourced by infalling axions have a high probability of converting back into axions before escaping the magnetosphere. In this work, we study the evolution of the axion and photon phase space near the surface of highly magnetized neutron stars in the adiabatic regime, quantifying for the first time the properties of the radio flux that arise at high axion-photon couplings. We show that previous attempts to mimic the scaling in this regime have been overly conservative in their treatment, and that the suppression can be largely circumvented for radio observations targeting neutron star populations.
title Adiabatic Axion-Photon Mixing Near Neutron Stars
topic High Energy Physics - Phenomenology
Cosmology and Nongalactic Astrophysics
High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2310.18403