A natural resolution for the Cabibbo angle anomaly and $R_{K^{(*)}}$
Abstract
We identify a single sixdimensional effective operator {$O_{\ell\ell}$} at the high scale, that can account for the Cabibbo angle anomaly by generating the desired operators at the low scale through renormalization group running, with the right magnitudes of Wilson coefficients. When generated as a result of a $Z'$ model, the nonuniversal leptonic couplings of this operator can also contribute to the lepton flavor universality violating $R_{K^{(*)}}$ anomaly, generating the preferred relation $C_9=C_{10}$ between the corresponding new physics Wilson coefficients. We argue that it is essential to have nonuniversal couplings of such a $Z'$ to all three generations of leptons for explaining both Cabibbo angle and $R_{K^{(*)}}$ anomalies simultaneously.
 Publication:

arXiv eprints
 Pub Date:
 August 2021
 arXiv:
 arXiv:2108.05614
 Bibcode:
 2021arXiv210805614A
 Keywords:

 High Energy Physics  Phenomenology;
 High Energy Physics  Experiment
 EPrint:
 5 Pages, 2 Figures, Major changes. Theoretical expressions and corresponding figure revised. The conditions at high scale, required to account for the anomalies, have been modified