750 GeV diphoton resonance and electric dipole moments

TL;DR

This paper explores how the 750 GeV diphoton excess could influence electric dipole moments of neutron and electron, linking new physics models to observable CP-violation effects within current experimental bounds.

Contribution

It provides a detailed analysis of the potential impact of the 750 GeV resonance on electric dipole moments, considering various models including vector-like fermions and composite pseudo-Nambu-Goldstone bosons.

Findings

Neutron EDM can be near current experimental bounds with CP-violating angle ~0.1.

Electron EDM can reach current bounds via Higgs mixing and CP violation with mixing angles ~10^{-3}.

In composite models, neutron EDM depends on hypercolor vacuum angle and resonance scale.

Abstract

We examine the implication of the recently observed 750 GeV diphoton excess for the electric dipole moments of the neutron and electron. If the excess is due to a spin zero resonance which couples to photons and gluons through the loops of massive vector-like fermions, the resulting neutron electric dipole moment can be comparable to the present experimental bound if the CP-violating angle {\alpha} in the underlying new physics is of O(10^{-1}). An electron EDM comparable to the present bound can be achieved through a mixing between the 750 GeV resonance and the Standard Model Higgs boson, if the mixing angle itself for an approximately pseudoscalar resonance, or the mixing angle times the CP-violating angle {\alpha} for an approximately scalar resonance, is of O(10^{-3}). For the case that the 750 GeV resonance corresponds to a composite pseudo-Nambu-Goldstone boson formed by a QCD-like hypercolor dynamics confining at \Lambda_HC, the resulting neutron EDM can be estimated with \alpha ~ (750 GeV / \Lambda_HC)^2\theta_HC, where \theta_HC is the hypercolor vacuum angle.