We search for lepton-flavor-violating τ-→e-α and τ-→μ-α decays, where α is an invisible spin-0 boson. The search uses electron-positron collisions at 10.58 GeV center-of-mass energy with an integrated luminosity of 62.8 fb-1, produced by the SuperKEKB collider and collected with the Belle II detector. We search for an excess in the lepton-energy spectrum of the known τ-→e-ν¯eντ and τ-→μ-ν¯μντ decays. We report 95% confidence-level upper limits on the branching-fraction ratio B(τ-→e-α)/B(τ-→e-ν¯eντ) in the range (1.1-9.7)×10-3 and on B(τ-→μ-α)/B(τ-→μ-ν¯μντ) in the range (0.7-12.2)×10-3 for α masses between 0 and 1.6 GeV/c2. These results provide the most stringent bounds on invisible boson production from τ decays.

Search for Lepton-Flavor-Violating τ Decays to a Lepton and an Invisible Boson at Belle II / Adachi, I., Adamczyk, K., Aggarwal, L., Ahmed, H., Aihara, H., Akopov, N., Aloisio, A., Anh Ky, N., Asner, D.M., Aushev, T., Aushev, V., Bae, H., Bahinipati, S., Bambade, P., Banerjee, S., Baudot, J., Bauer, M., Baur, A., Beaubien, A., Becker, J., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 130:18(2023). [10.1103/PhysRevLett.130.181803]

Search for Lepton-Flavor-Violating τ Decays to a Lepton and an Invisible Boson at Belle II

Aloisio A.;Campajola M.;De Nardo G.;Di Capua F.;Giordano R.;Merola M.;Russo G.;
2023

Abstract

We search for lepton-flavor-violating τ-→e-α and τ-→μ-α decays, where α is an invisible spin-0 boson. The search uses electron-positron collisions at 10.58 GeV center-of-mass energy with an integrated luminosity of 62.8 fb-1, produced by the SuperKEKB collider and collected with the Belle II detector. We search for an excess in the lepton-energy spectrum of the known τ-→e-ν¯eντ and τ-→μ-ν¯μντ decays. We report 95% confidence-level upper limits on the branching-fraction ratio B(τ-→e-α)/B(τ-→e-ν¯eντ) in the range (1.1-9.7)×10-3 and on B(τ-→μ-α)/B(τ-→μ-ν¯μντ) in the range (0.7-12.2)×10-3 for α masses between 0 and 1.6 GeV/c2. These results provide the most stringent bounds on invisible boson production from τ decays.
2023
Search for Lepton-Flavor-Violating τ Decays to a Lepton and an Invisible Boson at Belle II / Adachi, I., Adamczyk, K., Aggarwal, L., Ahmed, H., Aihara, H., Akopov, N., Aloisio, A., Anh Ky, N., Asner, D.M., Aushev, T., Aushev, V., Bae, H., Bahinipati, S., Bambade, P., Banerjee, S., Baudot, J., Bauer, M., Baur, A., Beaubien, A., Becker, J., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 130:18(2023). [10.1103/PhysRevLett.130.181803]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/938421
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