Constraints on axionlike particles with different magnetic field models from the PKS 2155304 energy spectrum
Abstract
Axionlike particles (ALPs) are a promising kind of dark matter candidate particle that are predicted to couple with photons in the presence of magnetic fields. The oscillations between photons and ALPs traveling in the magnetic fields have been used to constrain ALP properties. In this work, we obtain some new constraints on the ALP mass m _{a} and the photonALP coupling constant g with two different magnetic field models through TeV photons from PKS 2155304. The first is the discreteφ model in which the magnetic field has the orientation angle φ that changes discretely and randomly from one coherent domain to the next, and the second is the linearlycontinuousφ model in which the magnetic field orientation angle φ varies continuously across neighboring coherent domains. For the discreteφ model, we can obtain the best constraints on the ALP mass m _{1} = m _{a}/(1 neV) = 0.1 and on the photonALP coupling constant g _{11} = g/(10^{11} GeV^{1}) = 5. The reasonable range of the ALP mass m _{1} is 0.08 ∼ 0.2 when g _{11} = 5, and the only reasonable value of the photonALP coupling constant is g _{11} = 5 when m _{1} = 0.1. For the linearlycontinuousφ model, we can obtain the best constraints on the ALP mass m _{1} = 0.1 and on the photonALP coupling constant g _{11} = 0.7. The reasonable range of the ALP mass m _{1} is 0.05 ∼ 0.4 when g _{11} = 0.7, and the reasonable range of the photonALP coupling constant g _{11} is 0.5 ∼ 1 when m _{1} = 0.1. All of the results are consistent with the upper bound (g < 6.6 × 10^{11} GeV^{1}, i.e., g _{11} < 6.6) set by the CAST experiment.
 Publication:

Research in Astronomy and Astrophysics
 Pub Date:
 October 2019
 DOI:
 10.1088/16744527/19/10/154
 arXiv:
 arXiv:1906.00357
 Bibcode:
 2019RAA....19..154B
 Keywords:

 Astrophysics  High Energy Astrophysical Phenomena
 EPrint:
 11 pages, 6 figures