Lepton flavor violating Z^′ explanation of the muon anomalous magnetic moment

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• 作者：Wolfgang Altmannshofer^a ; Chien-Yi Chen^b ; ^c ; P.S. Bhupal Dev^d ; ^{bhupal.dev@mpi-hd.mpg.de" class="auth_mail" title="E-mail the corresponding author} ; Amarjit Soni^e
• 关键词：Muon anomalous magnetic moment ; Light gauge boson ; Lepton flavor violation
• 刊名：Physics Letters B
• 出版年：2016
• 出版时间：10 November 2016
• 年：2016
• 卷：762
• 期：Complete
• 页码：389-398
• 全文大小：1075 K

文摘

We discuss a minimal solution to the long-standing (g−2)_μ${(g-2)}_{\mu }$ anomaly in a simple extension of the Standard Model with an extra Z^′$Z^{\prime }$ vector boson that has only flavor off-diagonal couplings to the second and third generation of leptons, i.e. μ,τ,ν_μ,ν_τ$\mu ,\tau ,{\nu }_{\mu },{\nu }_{\tau }$ and their antiparticles. A simplified model realization, as well as various collider and low-energy constraints on this model, are discussed. We find that the (g−2)_μ${(g-2)}_{\mu }$-favored region for a Z^′$Z^{\prime }$ lighter than the tau lepton is totally excluded, while a heavier Z^′$Z^{\prime }$ solution is still allowed. Some testable implications of this scenario in future experiments, such as lepton-flavor universality-violating tau decays at Belle 2, and a new four-lepton signature involving same-sign di-muons and di-taus at HL-LHC and FCC-ee, are pointed out. A characteristic resonant absorption feature in the high-energy neutrino spectrum might also be observed by neutrino telescopes like IceCube and KM3NeT.