Flavor Violation in the Scalar Sector

TL;DR

This paper explores flavor-changing couplings of the Higgs boson in extended models, analyzing constraints and proposing new detection channels at the LHC, with implications for flavor and CP violation.

Contribution

It identifies unexplored LHC final states for flavor violation in the scalar sector, especially in Two Higgs Doublet Models, and provides detailed phenomenological analyses.

Findings

Constraints on flavor-changing Higgs couplings from rare decays

Potential detection channels like $pp o t h$ and $pp o t H^0$

Implications for flavor and CP violation in extended Higgs models

Abstract

In many extensions of the Standard Model, the alignment in flavor space of the fermion mass matrices and the Yukawa coupling matrices can be broken. The physical scalar boson $h(125)$ could then have flavor changing couplings. In this talk, we summarize constraints on such couplings from rare decay searches, and we investigate current and future detection prospects at the LHC. We emphasize the importance of several yet unexplored final states: (i) anomalous single top + $h$ production in $p p \to t h$, arising from $tuh$ couplings (but not from the more widely studied $tch$ couplings); (ii) $p p \to t + (H^0 \to h h)$ through $tuh$ couplings in the context of a Two Higgs Doublet Model (2HDM), perhaps the simplest model with flavor violation in the scalar sector; (iii) $p p \to H^0 \to \tau\mu$ in the 2HDM context. For all of these processes, we perform a detailed phenomenological studies. Finally, we comment on the possibility of flavor violation combined with CP violation, which may be interesting if the current CMS hint for $h \to \tau\mu$ gets corroborated.