Interference Effects in Higgs production through Vector Boson Fusion in the Standard Model and its Singlet Extension

TL;DR

This paper investigates interference effects in Higgs production via Vector Boson Fusion within the Standard Model and its Singlet extension, highlighting their importance for accurate theoretical predictions and Higgs width estimation.

Contribution

It extends previous studies of interference effects to Vector Boson Scattering, analyzing their impact in both the Standard Model and a Singlet extension of the Higgs sector.

Findings

Interference effects significantly influence Higgs production predictions.

Large cancellations can occur due to multiple neutral scalars.

Implications for Higgs width measurements and unitarity restoration.

Abstract

Interference effects play an important role in Electroweak Physics. They are responsible for the restoration of unitarity al large energies. When, as is often the case, higher order corrections are only available for some particular subamplitude, interferences need to be carefully computed in order to obtain the best theoretical prediction. In the new proposal to estimate the total Higgs width from the off shell cross section, the interference between the Higgs signal and the background is essential. It has been recently pointed out in gluon fusion that whenever more than one neutral, CP even, scalars are present in the spectrum large cancellations can occur. We extend these studies to Vector Boson Scattering, examining interference effects in the Higgs sector in the Standard Model and its one Higgs Singlet extension.