Composite Higgs revealed in Higgs pair photo-production at future colliders

TL;DR

Future electron-positron colliders can potentially discover composite Higgs models through Higgs pair production via photon collisions, revealing deviations from the Standard Model in Higgs couplings and new resonances.

Contribution

This paper demonstrates the sensitivity of Higgs pair production in photon collisions at future colliders to composite Higgs models, highlighting observable deviations from the Standard Model.

Findings

Deviations in Higgs couplings due to composite models.

Significant effects from Higgs-top quartic coupling.

Potential detection of light scalar resonances.

Abstract

The next generation electron-positron colliders are designed for precision studies of the Standard Model and its extensions, in particular in the Higgs sector. We consider the potential for discovery of composite Higgs models in Higgs pair production through photon collisions. This process is loop-generated, thus it provides access to all Higgs couplings and can show new physics effects in polarized and unpolarized cross-sections starting at relatively low collider energies. It is, therefore, relevant for all electron-positron colliders planned or in preparation. Sizeable deviations from the Standard Model predictions are present in a general class of composite Higgs models, as couplings of one or more Higgs bosons to fermions, or fermionic and scalar resonances, modify the destructive interference present in the Standard Model. In particular, large effects are due to the new quartic coupling of the Higgs to tops and to the presence of a light scalar resonance.