Pati-Salam explanations of the B-meson anomalies

Abstract

Abstract We provide a combined explanation of the increasingly tantalizing B-meson anomalies, both in R K ∗ $$ {R}_{K^{\left(\ast \right)}} $$ and R D ∗ $$ {R}_{D^{\left(\ast \right)}} $$ , in the Pati-Salam model with minimal matter content. This well-known model, based on the gauge group SU(4) LC × SU(2) L × SU(2) R , naturally contains a variety of scalar leptoquarks with related and restricted couplings. In particular we show that the seesaw-motivated scalar leptoquark within the representation ( 10 ¯ $$ \overline{\mathbf{10}} $$ , 3 , 1) and its right-handed parity partner ( 10 ¯ $$ \overline{\mathbf{10}} $$ , 1 , 3) can solve both anomalies while making testable predictions for related observables such as B → Kνν and B → Kμτ. The solution of the R K ∗ $$ {R}_{K^{\left(\ast \right)}} $$ anomaly alone can be related to a type-II seesaw neutrino mass structure. Explaining also R D ∗ $$ {R}_{D^{\left(\ast \right)}} $$ requires the existence of a light right-handed neutrino, which constrains the UV structure of the model.

Keywords

• Beyond Standard Model
• Gauge Symmetry
• Heavy Quark Physics
• Neutrino Physics