PubDB | BELLE2-PUB-DRAFT-2024-020

Abstract	We report research on Axion-Like-Particle(ALP) through B → K a'(a' → γγ) channel. in this research, we are looking for ALP which decay into a pair of photons. Without expectation of the ALP mass, we scan the kinematically allowed mass region of the ALP by dividing the search region into small windows from 0.16 GeV/c^2 to 4.50 GeV/c^2 (K+ , K_S0 modes) or 4.2 GeV/c 2 (K∗0 , K∗+ mode). We use the Belle experiment Monte-Carlo (MC) simulation sample to obtain the expected upper limit of BF(B → Ka') for each ALP mass scan point.the 90% confidence level upper limits on ga′ W coupling for each ALP mass hypothesis are established as function of the ALP mass. The result improve current constraint on ga′ W .
Tags	Belle
Working group	Dark Sector and Low Multiplicity
Principal authors	@ Sungjin Cho, Youngjoon Kwon
Reference	submitted to JHEP
Links	arXiv:2507.01249,

Abstract

We report research on Axion-Like-Particle(ALP) through B → K a'(a' → γγ) channel. in this research, we are looking for ALP which decay into a pair of photons. Without expectation of the ALP mass, we scan the kinematically allowed mass region of the ALP by dividing the search region into small windows from 0.16 GeV/c^2 to 4.50 GeV/c^2 (K+ , K_S0 modes) or 4.2 GeV/c 2 (K∗0 , K∗+ mode). We use the Belle experiment Monte-Carlo (MC) simulation sample to obtain the expected upper limit of BF(B → Ka') for each ALP mass scan point.the 90% confidence level upper limits on ga′ W coupling for each ALP mass hypothesis are established as function of the ALP mass. The result improve current constraint on ga′ W .

Search for ALP through B→Ka'(a'→γγ) decay at Belle