Betelgeuse constraints on coupling between axionlike particles and electrons
Abstract
Axionlike particles (ALPs) can be produced by thermal processes in a stellar interior, escape from the star and, if sufficiently light, be converted into photons in the external Galactic magnetic field. Such a process could produce a detectable hard x-ray excess in the direction of the star. In this scenario, a promising class of targets is the red supergiants, massive stars which are experiencing the late part of their evolution. We report on a search for ALP-induced x-ray emission from Betelgeuse, produced via the combined processes of bremsstrahlung, Compton and Primakoff. Using a 50 ks observation of Betelgeuse by the NuSTAR satellite telescope, we set 95% C.L. upper limits on the ALP-electron (ga e) and ALP-photon (ga γ) couplings. For masses ma≤(3.5 - 5.5 )×10-11 eV , we find ga γ×ga e<(0.4 - 2.8 )×10-24 GeV-1 (depending on the stellar model and assuming a value of the regular Galactic magnetic field in the direction transverse to Betelgeuse of BT=1.4 μ G ). This corresponds to ga e<(0.4 - 2.8 )×10-12 for ga γ>1.0 ×10-12 GeV-1 . This analysis supercedes by over an order of magnitude the limit on ga e×ga γ placed by the CAST solar axion experiment and is among the strongest constraints on these couplings.
- Publication:
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Physical Review D
- Pub Date:
- December 2022
- DOI:
- arXiv:
- arXiv:2204.03121
- Bibcode:
- 2022PhRvD.106l3019X
- Keywords:
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- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- Phys. Rev. D. 106, 123019 (2022)