Higgs Underproduction at the LHC

TL;DR

This paper demonstrates that the production of the Higgs boson via gluon fusion can be significantly suppressed by colored scalars, potentially allowing the Higgs to evade current LHC detection limits.

Contribution

It introduces a mechanism where colored scalars cause destructive interference in Higgs production, showing how this can suppress signals and affect Higgs search strategies at the LHC.

Findings

Gluon fusion can be suppressed by over an order of magnitude with colored scalars.

Suppression depends on scalar mass and coupling strength.

Colored scalars are produced in pairs, leading to detectable multi-jet signatures.

Abstract

We show that production of the Higgs boson through gluon-fusion may be suppressed in the presence of colored scalars. Substantial destructive interference between the top quark diagrams and colored scalar diagrams is possible due to cancellations between the real (and also imaginary) parts of the amplitudes. As an example, we consider a color-octet scalar that has a negative, order one coupling to the Higgs doublet. We find that gluon fusion can be suppressed by more than an order of magnitude when the scalar mass is below a few hundred GeV, while milder suppressions occur for larger scalar masses or smaller couplings. Thus, the standard model extended with only one particle can evade the full range of present LHC exclusion limits on the Higgs mass. The colored scalars, however, would be produced in pairs with a large rate at the LHC, leading to multi-jet final states to which the LHC experiments are now becoming sensitive.