Higgs Flavor Violation as a Signal to Discriminate Models

TL;DR

This paper investigates the potential of Higgs lepton flavor violation as a way to distinguish between new physics models, analyzing constraints and identifying which models could explain observed signals.

Contribution

It provides a model-independent analysis of Higgs flavor violation and evaluates specific new physics models for their ability to account for the CMS excess.

Findings

Type-III Two Higgs Doublet Models can explain the excess.

Higgs portal-like models are also viable.

SUSY and Composite Higgs models are unlikely explanations.

Abstract

We consider the Higgs Lepton Flavor Violating process $h \rightarrow \tau \mu$, in which CMS found a $2.5 \sigma$ excess of events, from a model independent perspective, and find that it is difficult to generate this operator without also obtaining a sizeable Wilson coefficient for the dipole operators responsible for tau radiative decay, constrained by BABAR to ${BR}(\tau \rightarrow \mu \gamma)< 4.4 \times 10^{-8} $. We then survey a set of representative models for new physics, to determine which ones are capable of evading this problem. We conclude that, should this measurement persist as a signal, type-III Two Higgs Doublet Models and Higgs portal-like models are favored, while SUSY and Composite Higgs models are unlikely to explain it.