Probing New Physics Signals with Symmetry-Restored Yukawa Textures

Abstract

We implement a symmetry violation guideline into a two-Higgs-doublet model embedded with three right-handed neutrinos, and exploit the generic Yukawa structures of the model via a hypothetical symmetry restoration of a global $U_Q(1{)}^3\times U_L(1{)}^3$ symmetry. We then apply a mass-powered parametrization to construct the phenomenologically motivated Yukawa interactions, which enables us to incorporate correlatively the neutrino mass, dark matter, as well as the lepton-flavor universality violations in $R_{K^{(\ast )}}$ and $R_{D^{(\ast )}}$. Specifically, two atmospheric-scale neutrino masses are generated by a low-scale seesaw mechanism, while the much lighter one, being of $\mathcal{O}(10^{-6})\mathrm{eV}$, is fixed by a $7.1\mathrm{keV}$ sterile neutrino dark matter produced primordially by the freeze-in mechanism. On the other hand, the neutrino and the charged-lepton mass hierarchies encoded in the mass-powered textures can naturally account for the $R_{K^{(\ast )}}$ and the $R_{D^{(\ast )}}$ anomalies, respectively. As a further application, a milder discrepancy of the muon $g-2$ is observed, which has also been implied by the recently refined lattice results.

Comments: 9 pages, 3 figures; formulation of the model refined, and several references added, final version published in the journal