Speaker
Description
Axion-like particles (ALPs) are one of the well-known particles beyond the standard model, so understanding its properties and interactions with standard model particles is important. In this study, we constrain the mass ($m_a$) and the photon coupling constant ($g_{a\gamma\gamma}$) of ALPs through light particle emission from primordial black holes (PBHs). To achieve this, we focus on the photon decay process of axion-like particle (ALP) which were continuously emitted from extragalactic primordial black holes (PBHs). Our research is divided into two parts. First, by comparing the direct photon spectrum from PBH with the sensitivity of e-ASTROGAM, the next generation of gamma-ray detectors, we obtain an upper limit of the PBH dark matter fraction. Second, we compute the upper limit of the PBH dark matter fraction again, but now with the total photon spectrum - a direct photon plus additional photon from the ALP decay. Next, we plot the two upper limit differences in the $m_a$-$g_{a\gamma\gamma}$ plane and get the region with significant differences. In this presentation, we will focus on the second part, the decay process of ALPs from PBH.
