Search for Axionlike Particles Produced in Collisions at Belle II

F Abudinén, I Adachi, H Aihara, N Akopov, A Aloisio… - Physical review …, 2020 - APS
F Abudinén, I Adachi, H Aihara, N Akopov, A Aloisio, F Ameli, N Anh Ky, DM Asner…
Physical review letters, 2020APS
We present a search for the direct production of a light pseudoscalar a decaying into two
photons with the Belle II detector at the SuperKEKB collider. We search for the process e+ e-
→ γ a, a→ γ γ in the mass range 0.2< ma< 9.7 GeV/c 2 using data corresponding to an
integrated luminosity of (445±3) pb-1. Light pseudoscalars interacting predominantly with
standard model gauge bosons (so-called axionlike particles or ALPs) are frequently
postulated in extensions of the standard model. We find no evidence for ALPs and set 95 …
We present a search for the direct production of a light pseudoscalar decaying into two photons with the Belle II detector at the SuperKEKB collider. We search for the process , in the mass range using data corresponding to an integrated luminosity of . Light pseudoscalars interacting predominantly with standard model gauge bosons (so-called axionlike particles or ALPs) are frequently postulated in extensions of the standard model. We find no evidence for ALPs and set 95% confidence level upper limits on the coupling strength of ALPs to photons at the level of . The limits are the most restrictive to date for .
American Physical Society