Effects of vectorlike leptons on $h\to 4\ell$ and the connection to the muon g-2 anomaly

Abstract

The mixing of new vectorlike leptons with leptons in the standard model can generate flavor violating couplings of $h$, $W$ and $Z$ between heavy and light leptons. Focusing on the couplings of the muon, the partial decay width of $h\to e_4^{\pm }{\mu }^{\mp }$, where $e_4$ is the new lepton, can be significant when this process is kinematically allowed. Subsequent decays $e_4^{\pm }\to Z{\mu }^{\pm }$ and $e_4^{\pm }\to W^{\pm }\nu$ lead to the same final states as $h\to Z{Z}^{\ast }\to Z{\mu }^{+}{\mu }^{-}$ and $h\to W{W}^{\ast }\to W\mu \nu$, thus possibly affecting measurements of these processes. We calculate $h\to e_4{\ell }_i\to Z{\ell }_i{\ell }_j$, where ${\ell }_{i,j}$ are standard model leptons, including the possibility of off-shell decays, interference with $h\to Z{Z}^{\ast }\to Z{\ell }_i{\ell }_i$, and the mass effect of ${\ell }_{i,j}$ which are important when the mass of $e_4$ is close to the mass of the Higgs boson. We derive constraints on masses and couplings of the heavy lepton from the measurement of $h\to 4\ell$. We focus on the couplings of the muon and discuss possible effects on $h\to Z{Z}^{\ast }$ from the region of parameters that can explain the anomaly in the measurement of the muon g-2.

26 pages, 14 figures, minor changes to match published version

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Cited by in corpus (15)

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• Correlating $h\to {\mu }^{+}{\mu }^{-}$ to the Anomalous Magnetic Moment of the Muon via Leptoquarks
• Prospects for vectorlike leptons at future proton-proton colliders
• Review of searches for vector-like quarks, vector-like leptons, and heavy neutral leptons in proton-proton collisions at $\sqrt{s}$ = 13 TeV at the CMS experiment
• Muon $g-2$ in two Higgs doublet models with vectorlike leptons
• Inclusive nonresonant multilepton probes of new phenomena at $\sqrt{s}=$ 13 TeV
• New constraints and discovery potential for Higgs to Higgs cascade decays through vectorlike leptons
• Impact of LHC data on muon $g-2$ solutions in vector-like extension of the Constrained MSSM
• Doubly charged scalars and vector-like leptons confronting the muon g-2 anomaly and Higgs vacuum stability
• Tau-jet signatures of vectorlike quark decays to heavy charged and neutral Higgs bosons
• The Ellipse of Muon Dipole Moments
• Current status on pair-produced muon-philic vectorlike leptons in multilepton channels at the LHC
• The Two Scales of New Physics in Higgs Couplings
• Long-lived Searches of Vector-like Lepton and Its Accompanying Scalar at Colliders