Higgs Pair Production as a Signal of Enhanced Yukawa Couplings.

Martin Bauer,Marcela Carena,Adrián Carmona

doi:10.1103/physrevlett.121.021801

Abstract

We present a nontrivial correlation between the enhancement of the Higgs-fermion couplings and the Higgs pair production cross section in two Higgs doublet models with a flavor symmetry, with implications for LHC searches. This symmetry suppresses flavor-changing neutral couplings of the Higgs boson and allows for a partial explanation of the hierarchy in the Yukawa sector. After taking into account the constraints from electroweak precision measurements, Higgs coupling strength measurements, and unitarity and perturbativity bounds, we identify an interesting region of parameter space leading to enhanced Yukawa couplings as well as enhanced di-Higgs gluon fusion production at the LHC reach. This effect is visible in both the resonant and nonresonant contributions to the Higgs pair production cross section. We encourage dedicated searches based on differential distributions as a novel way to indirectly probe enhanced Higgs couplings to light fermions.

Highlights

Introduction.—Probing the Higgs couplings to the first and second generation fermions is one of the main objectives of the Higgs program at the LHC
Eq (3) in general induces sizable flavor-changing neutral currents (FCNCs) mediated by the Higgs boson, due to the misalignment between fermion masses and Higgs couplings, which requires additional fine-tuning to fulfill the bounds from flavor observables [1]
In two Higgs doublet models (2HDMs) with a flavor symmetry, the light fermion masses can be explained through higher order operators, avoiding the need for the very small Yukawa couplings in the standard model (SM)

Summary

Introduction

Introduction.—Probing the Higgs couplings to the first and second generation fermions is one of the main objectives of the Higgs program at the LHC. In two Higgs doublet models (2HDMs) with a flavor symmetry, the light fermion masses can be explained through higher order operators, avoiding the need for the very small Yukawa couplings in the SM.

Results

Conclusion