e+ e- -> t anti-t H including decays: on the size of background contributions

TL;DR

This paper calculates the cross sections for e+e- to t anti-t H processes, including all standard model diagrams and backgrounds, highlighting the significance of background contributions for future collider measurements.

Contribution

It provides a comprehensive calculation of the lowest order cross sections for t anti-t H production, including background analysis and effects of initial state radiation.

Findings

Background contributions are large, especially QCD backgrounds.

Initial state radiation significantly affects cross sections.

Cross section dependence on Higgs and top quark masses is analyzed.

Abstract

We present results for the lowest order cross sections, calculated with the complete set of the standard model Feynman diagrams, of all possible detection channels of the associated production of the top quark pair and the light Higgs boson, which may be used for determination of the top-Higgs Yukawa coupling at the future e+e- linear collider. We show that, for typical particle identification cuts, the background contributions are large. In particular, the QCD background contributions are much bigger than could be expected when taking into account a possibly low virtuality of exchanged gluons. Moreover, we include the initial state radiation effects and discuss the dependence of the cross sections on the Higgs boson and top quark masses.