Betelgeuse constraints on coupling between axionlike particles and electrons

• 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 (gae) and ALP-photon (gaγ) couplings. For masses ma≤(3.5–5.5)×10−11  eV, we find gaγ×gae<(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  μG). This corresponds to gae<(0.4–2.8)×10−12 for gaγ>1.0×10−12  GeV−1. This analysis supercedes by over an order of magnitude the limit on gae×gaγ placed by the CAST solar axion experiment and is among the strongest constraints on these couplings.

Ämnesord

NATURVETENSKAP  -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)