Probing composite Higgs models by measuring phase shifts at LHC

TL;DR

This paper explores how measuring phase shifts in scattering amplitudes at the LHC can probe composite Higgs models, predicting new resonances and potential violations of unitarity at TeV scales.

Contribution

It introduces a method to estimate the resonance scale in composite Higgs models through phase shift analysis, drawing analogies with pion physics in QCD.

Findings

Phase shifts can indicate the resonance scale in composite Higgs models.

Detectability of phase shifts at LHC and ILC is feasible.

The approach provides a new way to test composite Higgs scenarios.

Abstract

Composite Higgs models are an attractive scenario, where the discovered Higgs boson is regarded as a Nambu-Goldstone boson associated with spontaneous breakdown of a global symmetry of more fundamental theory. This class of models predicts violation of perturbative unitarity at high energies, and new resonances are expected to appear around TeV scale to maintain the unitarity, while a sizable phase shift is predicted in certain scattering amplitude. We investigate the new resonance scale from the phase shift by drawing analogies with pion physics in QCD. The detectability of the phase shift at LHC and the ILC is also discussed. This talk was given in {\it HPNP 2015} at University of Toyama and based on the work in collaboration with S.~Kanemura, T.~Shindou and N.~Machida (arXiv:1410.8413 [hep-ph]).