Lineshape of the Higgs boson in future lepton colliders

TL;DR

This paper analyzes how photon emission and machine energy spread affect the Higgs boson production cross section at future lepton colliders, providing detailed numerical results and discussing uncertainties in the calculations.

Contribution

It presents a detailed calculation of the Higgs boson lineshape considering bremsstrahlung and machine energy spread effects, including numerical results and uncertainty analysis.

Findings

Cross section at resonance peak is significantly reduced by bremsstrahlung effects.

Machine energy spread further decreases the peak cross section.

Numerical results for various energy spreads are provided with discussion on uncertainties.

Abstract

The effect of the photon emission (bremsstrahlung) in the cross section of the process of direct production of the Higgs boson in the future high luminosity electron and muon colliders is calculated. It was found that cross section at the top of the Higgs boson resonance peak is reduced by factor 0.347 for the electron collider and 0.548 for the muon collider. Machine spread of the centre of the mass energy of 4.2MeV (equal to the Higgs width) would reduce peak cross section further, by factor 0.170 and 0.256 (QED and energy spread) for electron and muon beams respectively. Possible uncertainties in the resummed QED calculations are discussed. Numerical results for the lineshape cross section including QED and many values of the machine energy spread are provided.