The Higgs Decay Width in Multi-Scalar Doublet Models

TL;DR

This paper explores how multi-scalar doublet models can alter Higgs decay rates significantly without direct detection of new scalars at the LHC, emphasizing the importance of precise Higgs property measurements.

Contribution

It demonstrates that Higgs decay rates can be substantially modified in multi-scalar models even when new particles are not directly observable at the LHC.

Findings

Higgs decay to b bbar can differ from the Standard Model

Two photon and tau tau decay events can be significantly affected

New physics may be invisible at the LHC but detectable through Higgs measurements

Abstract

We show that there are regions of parameter space in multi-scalar doublet models where, in the first few hundred inverse femtobarns of data, the new charged and neutral scalars are not directly observable at the LHC and yet the Higgs decay rate to b bbar is changed significantly from its standard model value. For a light Higgs with a mass less than 140 GeV, this can cause a large change in the number of two photon and tau tau Higgs decay events expected at the LHC compared to the minimal standard model. In the models we consider, the principle of minimal flavor violation is used to suppress flavor changing neutral currents. This paper emphasizes the importance of measuring the properties of the Higgs boson at the LHC; for a range of parameters the model considered has new physics at the TeV scale that is invisible, in the first few hundred inverse femtobarns of integrated luminosity at the LHC, except indirectly through the measurement of Higgs boson properties.