$L_{\mu }-L_{\tau }$ gauge-boson production from lepton flavor violating $\tau$ decays at Belle II

Abstract

$L_{\mu }-L_{\tau }$ gauge boson ($Z^{\prime }$) with a mass in the MeV to GeV region can resolve not only the muon $g-2$ excess, but also the gap in the high-energy cosmic neutrino spectrum at IceCube. It was recently proposed that such a light gauge boson can be detected during the Belle II experiment with a luminosity of 50 ab${}^{-1}$ by the $e^+ e^- \to γ+\slashed{E}$ process through the kinetic mixing with the photon, where the missing energy $\slashed{E}$ is from the $Z^{\prime }\to \bar{\nu }\nu$ decays. We study the phenomenological implications when a pair of singlet vector-like leptons carrying different $L_{\mu }-L_{\tau }$ charges are included, and a complex singlet scalar (${\varphi }_S$) is introduced to accomplish the spontaneous $U(1{)}_{L_{\mu }-L_{\tau }}$ symmetry breaking. It is found that the extension leads to several phenomena of interest, including (i) branching ratio (BR) for $h\to \mu \tau$ can be of the order of $10^{-3}$; (ii) ${\varphi }_S$-mediated muon $g-2$ can be of the order of $10\times 10^{-10}$; (iii) BR for $\tau \to \mu {\varphi }_S^{\ast }\to \mu Z^{\prime }{Z}^{\prime }$ can be $10^{-8}$, and (iv) kinetic mixing between the $Z^{\prime }$ boson and photon is sensitive to the relative heavy lepton masses. The predicted BRs for $τ\to (3μ+\slashed{E}, 5μ$) through the leptonic $Z^{\prime }$ decays can reach a level of $10^{-9}$, in which the results fall within the sensitivity of the Belle II in the search for the rare tau decays.

23 pages, 7 figures, 4 tables, version to appear in Phys. Rev. D

References in corpus (12)

• Implications of CTEQ global analysis for collider observables
• Neutrino Trident Production: A Powerful Probe of New Physics with Neutrino Beams
• Explaining $h\to {\mu }^{\pm }{\tau }^{\mp }$, $B\to K^{\ast }{\mu }^{+}{\mu }^{-}$ and $B\to K{\mu }^{+}{\mu }^{-}/B\to K{e}^{+}{e}^{-}$ in a two-Higgs-doublet model with gauged $L_{\mu }-L_{\tau }$
• Explaining Dark Matter and $B$ Decay Anomalies with an $L_{\mu }-L_{\tau }$ Model
• Lepton flavor violating Z' explanation of the muon anomalous magnetic moment
• Higgs $\to \mu \tau$ in Abelian and Non-Abelian Flavor Symmetry Models
• Muon g-2 and searches for a new leptophobic sub-GeV dark boson in a missing-energy experiment at CERN
• Detecting the $L_{\mu }-L_{\tau }$ gauge boson at Belle II
• Neutrino Mass, Dark Matter and Anomalous Magnetic Moment of Muon in a $U(1{)}_{L_{\mu }-L_{\tau }}$ Model
• Flavour Dependent Gauged Radiative Neutrino Mass Model
• Mind the gap on Icecube: Cosmic neutrino spectrum and muon anomalous magnetic moment in the gauged L_μ - L_τ model
• On the possibility of search for $L_{\mu }-L_{\tau }$ gauge boson at Belle-II and neutrino beam experiments

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