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 þ e − → γa, a → γγ in the mass range 0.2 < m a < 9.7 GeV=c 2 using data corresponding to an integrated luminosity of ð445 3Þ 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 aγγ 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 .
Abudinén, F., Adachi, I., Aihara, H., Akopov, N., Aloisio, A., Ameli, F., et al. (2020). Search for Axionlike Particles Produced in e+e− Collisions at Belle II. PHYSICAL REVIEW LETTERS, 125(16), 161806 [10.1103/PhysRevLett.125.161806].
Search for Axionlike Particles Produced in e+e− Collisions at Belle II
Bernieri, E.Membro del Collaboration Group
;Bussino, S.Membro del Collaboration Group
;De Pietro, G.Membro del Collaboration Group
;Martini, A.Membro del Collaboration Group
;
2020-01-01
Abstract
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 þ e − → γa, a → γγ in the mass range 0.2 < m a < 9.7 GeV=c 2 using data corresponding to an integrated luminosity of ð445 3Þ 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 aγγ 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 .I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.