Implications of hidden gauged $U(1)$ model for $B$ anomalies

Understand

We propose a hidden gauged $U(1)_H$ $Z'$ model to explain deviations from the Standard Model (SM) values in lepton flavor universality known as $R_K$ and $R_D$ anomalies.

• The $Z'$ only interacts with the SM fermions via their mixing with vector-like doublet fermions after the $U(1)_H$ symmetry breaking, which leads to $b \to s \mu\mu$ transition through the $Z^{\prime}$ at tree level.
• Moreover, introducing an additional mediator, inert-Higgs doublet, yields $b\to c \tau \nu$ process via charged scalar contribution at tree level.
• Using flavio package, we scrutinize adequate sizes of the relevant Wilson coefficients to these two processes by taking various flavor observables into account.