LFV decays in a 3-3-1 model with singlet leptoquarks

Abstract

Motivated by a recent study of the 3-3-1 model supplemented with a singlet scalar leptoquark, which successfully explains the muon anomalous magnetic moment and the decay $\mu\to e\gamma$ within current experimental constraints, we extend the phenomenological analysis of this framework to include the lepton-flavor-violating decays of the Standard Model-like Higgs and the $Z$ boson. An interesting feature is that the branching ratios of these decays exhibit a nearly linear correlation with the corresponding charged lepton flavor-violating radiative decays, namely $\mathrm{Br}(h,Z\to e_b^\pm e_a^\mp)\propto\mathrm{Br}(e_b\to e_a\gamma)$. Furthermore, the model exhibits a complementary interplay between the charged-lepton anomalous magnetic moments: parameter regions with $|\Delta a_{\mu}|\geq10^{-11}$ favor $\mathrm{Br}(h,Z\to\tau^\pm\mu^\mp)$ reaching their current experimental upper limits while keeping $|\Delta a_e|$ negligible, whereas regions with $10^{-14}\leq|\Delta a_e|\leq 8\times10^{-13}$ instead allow $\mathrm{Br}(h,Z\to\tau^\pm e^\mp)$ to approach the present experimental sensitivities but simultaneously suppress $|\Delta a_\mu|$ to the level of $\mathcal{O}(10^{-16})$.