Low-energy signatures of the ${\mathrm{PS}}^3$ model: from $B$-physics anomalies to LFV

Abstract

The three-site Pati-Salam gauge model provides a consistent description for the hints of lepton-flavor non-universality observed in $B$ decays, connecting the present pattern of "anomalies" to the origin of the Standard Model Yukawa couplings. We present here a detailed analysis of the model predictions for a series of low-energy observables, mainly in $B$ and $\tau$ physics. The model is in good agreement with present data and predicts a well-defined pattern of non-standard effects in low-energy observables that could allow us to test it in the near future. Particularly interesting are the predictions of large $\tau \to \mu$ Lepton Flavor Violating processes, such as $\tau \to \mu \gamma$, $\tau \to 3\mu$, $B\to K\tau \mu$, and $B_s\to \tau \mu$. Also $\mu \to 3e$, $\mu \to e\gamma$, and $K_L\to \mu e$ decays could be not far from the present exclusion bounds, although this conclusion is more model dependent.

Comments: 47 pages, 18 figures. v2: typos corrected and references added. Extended discussion on the model parameters. Matching the journal version