Speaker
Description
Axion-Like Particles (ALPs) are a broader class of pseudo-Nambu-Goldstone bosons that arise in various extensions of the Standard Model (SM), especially in string theory compactifications. ALPs may be produced in the reactor core via Primakoff conversion and Compton-like processes. We report a laboratory-based search for ALPs using data from the TEXONO experiment at the Kuo-Sheng Reactor Neutrino Laboratory (KSNL) with a high-purity germanium detector of mass 1.06 kg at a distance of 28 m from the 2.9 GW reactor core. The analysis probes inverse Primakoff scattering, inverse Compton conversion, axio-electric process, and decay-in-flight signatures. Based on 278.91/43.60 days of Reactor ON/OFF data, no statistically significant excess above background was observed. Hence, 90% confidence level upper limits on the ALP-photon coupling $g_{a\gamma\gamma}$ and ALP-electron coupling gaee are derived for ALP masses between 1 eV and 1 MeV. We also present a model independent analysis of the direct detection of reactor ALPs by precisely accounting for the interference between various detection channels.