Muon ($g-2$) in $U(1)_{L_μ-L_τ}$ Scotogenic Model Extended with Vector like Fermion

Abstract

The latest results of anomalous muon magnetic moment at Fermilab show a discrepancy of 4.2 $σ$ between the Standard Model (SM) prediction and experimental value. In this work, we revisit $U(1)_{L_μ-L_τ}$ symmetry with in the paradigm of scotogenic model which explains muon ($g-2$) and neutrino mass generation, simultaneously. The mass of new gauge boson $M_{Z_{μτ}}$ generated after the spontaneous symmetry breaking of $U(1)_{L_μ-L_τ}$ is constrained, solely, in light of the current neutrino oscillation data to explain muon ($g-2$). In particular, we have obtained two regions I and II, around 150 MeV and 500 MeV, respectively, in $M_{Z_{μτ}}-g_{μτ}$ plane which explain the neutrino phenomenology. Region I is found to be consistent with muon neutrino trident (MNT) bound ($g_{μτ}$ $\leq$ $10^{-3}$) to explain muon ($g-2$), however, region II violates it for mass range $M_{Z_{μτ}}>300$ MeV. We, then, extend the minimal gauged scotogenic model by a vector like lepton (VLL) triplet $ψ_T$. The mixing of $ψ_T$ with inert scalar doublet $η$ leads to chirally enhanced positive contribution to muon anomalous magnetic moment independent of $Z_{μτ}$ mass. Furthermore, we have, also, investigated the implication of the model for $0νββ$ decay and $CP$ violation. The non-observation of $0νββ$ decay down to the sensitivity of 0.01 eV shall refute the model. The model, in general,is found to be consistent with both $CP$ conserving and $CP$ violating solutions.