Non-renormalizable Yukawa Interactions and Higgs Physics

TL;DR

This paper investigates a Standard Model scenario where Yukawa couplings are suppressed or forbidden, leading to enhanced Higgs-fermion interactions via dimension six operators, significantly affecting collider phenomenology and Higgs mass bounds.

Contribution

It introduces a framework where Yukawa interactions are dominated by dimension six operators, altering Higgs couplings and collider signatures compared to the Standard Model.

Findings

Higgs production via gluon fusion increases ninefold.

Higgs decay widths to fermions are enhanced, while to photons are reduced.

Tevatron exclusion range for Higgs mass extends to 142-200 GeV.

Abstract

We explore a scenario in the Standard Model in which dimension four Yukawa couplings are either forbidden by a symmetry, or happen to be very tiny, and the Yukawa interactions are dominated by effective dimension six interactions. In this case, the Higgs interactions to the fermions are enhanced in a large way, whereas its interaction with the gauge bosons remains the same as in the Standard Model. In hadron colliders, Higgs boson production via gluon gluon fusion increases by a factor of nine. Higgs decay widths to fermion anti-fermion pairs also increase by the same factor, whereas the decay widths to photon photon and gamma Z are reduced. Current Tevatron exclusion range for the Higgs mass increases to ~ 142-200 GeV in our scenario, and new physics must appear at a scale below a TeV.