High-energy suppression of the Higgsstrahlung cross-section in the Minimal Composite Higgs Model

TL;DR

This paper investigates how Higgs boson compositeness leads to a suppression of the Higgsstrahlung cross-section at high energies within the Minimal Composite Higgs Model, highlighting potential collider signatures.

Contribution

It provides the first detailed calculation of Higgsstrahlung suppression in a warped five-dimensional composite Higgs model and discusses measurable collider effects.

Findings

Higgsstrahlung cross section is strongly suppressed above the Kaluza-Klein scale.

Suppression is due to cancellations among Kaluza-Klein mode contributions.

The coupling of the first Kaluza-Klein mode can be experimentally measured.

Abstract

If the Higgs boson is composite, signs of this compositeness should appear via a formfactor-like suppression of Higgs scattering cross sections at momentum transfers above the compositeness scale. We explore this by computing the cross section for e+e- ---> ZH (Higgsstrahlung) in a warped five-dimensional gauge-Higgs unification model known as the Minimal Composite Higgs Model (MCHM). We observe that the Higgsstrahlung cross section in the MCHM is strongly suppressed compared to that in the Standard Model at center-of-mass energies above the scale of the first Kaluza-Klein excitations, due to cancellations among the contributions of successive Z boson Kaluza-Klein modes. We also show that the magnitude and sign of the coupling of the first Kaluza-Klein mode can be measured at a future electron-positron collider such as the proposed International Linear Collider or Compact Linear Collider.