E6 inspired composite Higgs model and 750 GeV diphoton excess

TL;DR

This paper proposes an E6 inspired composite Higgs model where a 750 GeV pseudoscalar particle could explain the observed diphoton excess at the LHC, linking new strong dynamics with experimental signals.

Contribution

It introduces a novel composite Higgs framework based on E6 symmetry breaking that naturally predicts a 750 GeV pseudoscalar explaining the diphoton excess.

Findings

Predicts a 750 GeV pseudoscalar with sufficient production cross section

Links the pseudoscalar to exotic fermions and gauge coupling unification

Provides a theoretical basis for the diphoton excess observation

Abstract

In the E6 inspired composite Higgs model (E6CHM) the strongly interacting sector possesses an SU(6)\times U(1)_B\times U(1)_L global symmetry. Near scale f\gtrsim 10 TeV the SU(6) symmetry is broken down to its SU(5) subgroup, that involves the standard model (SM) gauge group. This breakdown of SU(6) leads to a set of pseudo--Nambu--Goldstone bosons (pNGBs) including a SM--like Higgs and a SM singlet pseudoscalar A. Because of the interactions between A and exotic fermions, which ensure the approximate unification of the SM gauge couplings and anomaly cancellation in this model, the couplings of the pseudoscalar A to gauge bosons get induced. As a result, the SM singlet pNGB state A with mass around 750 GeV may give rise to sufficiently large cross section of pp\to \gamma\gamma that can be identified with the recently observed diphoton excess.