PT Journal
AU Belle II Collaboration (Abudinen, Fea
   Gomis, P
   Marinas, C
TI Search for Axionlike Particles Produced in e(+)e(-) Collisions at Belle II
SO Physical Review Letters
JI Phys. Rev. Lett.
PY 2020
BP 161806
EP 9pp
VL 125
IS 16
DI 10.1103/PhysRevLett.125.161806
LA English
AB 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(-) -> gamma a, a -> gamma gamma in the mass range 0.2 < m(a) < 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% confidence level upper limits on the coupling strength g(a gamma gamma) of ALPs to photons at the level of 10(-3) GeV-1. The limits are the most restrictive to date for 0.2 < m(a) < 1 GeV/c(2).
ER