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-→γa, a→γγ in the mass range 0.2<9.7 GeV/c2 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 gaγγ of ALPs to photons at the level of 10-3 GeV-1. The limits are the most restrictive to date for 0.2<1 GeV/c2.
Search for Axionlike Particles Produced in e+e- Collisions at Belle II / Belle II, Collaboration; Aloisio, A.; Campajola, M.; De Nardo, G.; Di Capua, F.; Giordano, R.; Merola, M.; Pardi, S.; Et, Al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 125:16(2020). [10.1103/PhysRevLett.125.161806]
Search for Axionlike Particles Produced in e+e- Collisions at Belle II
Aloisio A.;Campajola M.;De Nardo G.;Di Capua F.;Giordano R.;Merola M.;Pardi S.;
2020
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+e-→γa, a→γγ in the mass range 0.2<9.7 GeV/c2 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 gaγγ of ALPs to photons at the level of 10-3 GeV-1. The limits are the most restrictive to date for 0.2<1 GeV/c2.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
