Twin Pati-Salam theory of flavour for a new picture of $B$-anomalies

Abstract

We discuss a theory of flavour which can simultaneously explain and connect the origin of the Standard Model flavour hierarchies with the $U_1(3,1,2/3)$ leptoquark explanation of the $B$-decay flavour anomalies. First, we motivate the vector leptoquark $U_1$ as an excellent mediator to address the updated picture of $B$-anomalies. Secondly, we introduce the Twin Pati-Salam theory of flavour, which naturally provides a low scale 4321 gauge group with a TeV scale $U_1$. We show that both the couplings of $U_1$ to SM fermions and the effective SM Yukawa couplings arise from the same physics, naturally providing a pattern of dominantly left-handed $U_1$ couplings as most preferred by current data. Finally, we discuss the most promising signals at low energy processes that can test the model in the near future.

Comments: 6 pages, 2 figures, contribution to the 2023 Electroweak session of the 57th Rencontres de Moriond