Resonance--Continuum Interference in Light Higgs Boson Production at a Photon Collider

TL;DR

This paper investigates the interference effects between the Standard Model Higgs resonance and background in gamma gamma collisions, quantifying the suppression of the Higgs signal and its dependence on model parameters.

Contribution

It provides a detailed calculation of interference effects including virtual gluon corrections for a light Higgs at a photon collider, highlighting potential deviations from Standard Model predictions.

Findings

Interference causes a 0.1-0.2% suppression of the Higgs peak.

Suppression is smaller than experimental accuracy but can be larger with modified Higgs couplings.

The effect depends on Higgs mass and scattering angle.

Abstract

We study the effect of interference between the Standard Model Higgs boson resonance and the continuum background in the process gamma gamma -> H -> b b-bar at a photon collider. Taking into account virtual gluon exchange between the final-state quarks, we calculate the leading corrections to the height of the resonance for the case of a light (m_H < 160 GeV) Higgs boson. We find that the interference is destructive and around 0.1--0.2% of the peak height, depending on the mass of the Higgs and the scattering angle. This suppression is smaller by an order of magnitude than the anticipated experimental accuracy at a photon collider. However, the fractional suppression can be significantly larger if the Higgs coupling to b quarks is increased by physics beyond the Standard Model.