Speaker
Description
Axion-like particles (ALPs) with MeV masses can be produced with semi-relativistic velocities in core-collapse supernovae (SNe). In this talk, I will demonstrate that a diffuse galactic flux of ALPs arises from the accumulated fluxes of past SNe and that these ALPs can be detected in neutrino water Cherenkov detectors via $a$ $p$ $\rightarrow$ $p$ $\gamma$ interactions. Using Super-Kamiokande data, I will present new constraints on the ALP parameter space, excluding a region above cooling bounds for ALP masses in the range of 1−80 MeV and ALP-proton couplings between $8 \times 10^{−6}$ and $2 \times 10^{−4}$. Furthermore, I will show that the future Hyper-Kamiokande will be able to probe couplings as small as $2.5 \times 10^{−6}$, fully closing the allowed region between current Super-Kamiokande diffuse ALP flux limits and the SN 1987A cooling bounds.
