RD*,RK* $$ {R}_{D^{\left(*\right)}},{R}_{K^{\left(*\right)}} $$ and neutrino mass in the 2HDM-III with right-handed neutrinos

Abstract

Abstract Given that the two-Higgs-doublet model of type III (2HDM-III) has the potential to address the RD* $$ {R}_{D^{\left(*\right)}} $$ anomalies while the resolution to the RK* $$ {R}_{K^{\left(*\right)}} $$ deficits requires new degrees of freedom within this framework, we consider in this paper a unified scenario where the low-scale type-I seesaw mechanism is embedded into the 2HDM-III, so as to accommodate the RD* $$ {R}_{D^{\left(*\right)}} $$ and RK* $$ {R}_{K^{\left(*\right)}} $$ anomalies as well as the neutrino mass. We first revisit the RD* $$ {R}_{D^{\left(*\right)}} $$ anomalies and find that the current world-averaged results can be addressed at 2σ level without violating the bound from the branching ratio ℬBc−→τ−ν¯ $$ \mathrm{\mathcal{B}}\left({B}_c^{-}\to {\tau}^{-}\overline{\nu}\right) $$ ≤ 30%. The scenario predicts two sub-eV neutrino masses based on a decoupled heavy Majorana neutrino and two nearly degenerate Majorana neutrinos with mass around the electroweak scale. For the RK* $$ {R}_{K^{\left(*\right)}} $$ anomalies, the same scenario can generate the required Wilson coefficients in the direction C 9 μ NP = − C 10 μ NP < 0, with O1 $$ \mathcal{O}(1) $$ Yukawa couplings for the muon and the top quark.

Keywords

• Beyond Standard Model
• Heavy Quark Physics