750 GeV diphoton resonance and electric dipole moments

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 750GeV 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 similar to(750GeV/similar to HC) (2)theta(HC), where theta(HC) is the hypercolor vacuum angle. (C) 2016 The Author(s). Published by Elsevier B.V