@article{e93c2290a033410e960faee1e8a41276,
title = "Search for an Invisibly Decaying Z′ Boson at Belle II in e+e- →μ+μ- (e±μ) Plus Missing Energy Final States",
abstract = "Theories beyond the standard model often predict the existence of an additional neutral boson, the Z′. Using data collected by the Belle II experiment during 2018 at the SuperKEKB collider, we perform the first searches for the invisible decay of a Z′ in the process e+e-→μ+μ-Z′ and of a lepton-flavor-violating Z′ in e+e-→e±μZ′. We do not find any excess of events and set 90% credibility level upper limits on the cross sections of these processes. We translate the former, in the framework of an Lμ-Lτ theory, into upper limits on the Z′ coupling constant at the level of 5×10-2-1 for MZ′≤6 GeV/c2.",
author = "{(Belle II Collaboration)} and I. Adachi and P. Ahlburg and H. Aihara and N. Akopov and A. Aloisio and {Anh Ky}, N. and Asner, {D. M.} and H. Atmacan and T. Aushev and V. Aushev and T. Aziz and V. Babu and S. Baehr and P. Bambade and Sw Banerjee and V. Bansal and M. Barrett and J. Baudot and J. Becker and Behera, {P. K.} and Bennett, {J. V.} and E. Bernieri and Bernlochner, {F. U.} and M. Bertemes and M. Bessner and S. Bettarini and F. Bianchi and D. Biswas and A. Bozek and M. Bra{\v c}ko and P. Branchini and Briere, {R. A.} and Browder, {T. E.} and A. Budano and L. Burmistrov and S. Bussino and M. Campajola and L. Cao and G. Casarosa and C. Cecchi and D. {\v C}ervenkov and Chang, {M. C.} and R. Cheaib and V. Chekelian and Chen, {Y. Q.} and Chen, {Y. T.} and Cheon, {B. G.} and K. Chilikin and K. Cho and S. Paul",
note = "Publisher Copyright: {\textcopyright} 2020 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the {"}https://creativecommons.org/licenses/by/4.0/{"} Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP.",
year = "2020",
month = apr,
day = "10",
doi = "10.1103/PhysRevLett.124.141801",
language = "English",
volume = "124",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "14",
}