The Lμ-Lτ extension of the standard model predicts the existence of a lepton-flavor-universality-violating Z′ boson that couples only to the heavier lepton families. We search for such a Z′ through its invisible decay in the process e+e-→μ+μ-Z′. We use a sample of electron-positron collisions at a center-of-mass energy of 10.58 GeV collected by the Belle II experiment in 2019-2020, corresponding to an integrated luminosity of 79.7 fb-1. We find no excess over the expected standard-model background. We set 90%-confidence-level upper limits on the cross section for this process as well as on the coupling of the model, which ranges from 3×10-3 at low Z′ masses to 1 at Z′ masses of 8 GeV/c2.

Search for an Invisible Z′ in a Final State with Two Muons and Missing Energy 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, Sw., Baudot, J., Bauer, M., Baur, A., Beaubien, A., Becker, J., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 130:23(2023). [10.1103/PhysRevLett.130.231801]

Search for an Invisible Z′ in a Final State with Two Muons and Missing Energy at Belle II

Aloisio, A.;Campajola, M.;De Nardo, G.;Giordano, R.;Merola, M.;Russo, G.;
2023

Abstract

The Lμ-Lτ extension of the standard model predicts the existence of a lepton-flavor-universality-violating Z′ boson that couples only to the heavier lepton families. We search for such a Z′ through its invisible decay in the process e+e-→μ+μ-Z′. We use a sample of electron-positron collisions at a center-of-mass energy of 10.58 GeV collected by the Belle II experiment in 2019-2020, corresponding to an integrated luminosity of 79.7 fb-1. We find no excess over the expected standard-model background. We set 90%-confidence-level upper limits on the cross section for this process as well as on the coupling of the model, which ranges from 3×10-3 at low Z′ masses to 1 at Z′ masses of 8 GeV/c2.
2023
Search for an Invisible Z′ in a Final State with Two Muons and Missing Energy 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, Sw., Baudot, J., Bauer, M., Baur, A., Beaubien, A., Becker, J., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 130:23(2023). [10.1103/PhysRevLett.130.231801]
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/938418
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 25
  • ???jsp.display-item.citation.isi??? 4
social impact