LHC 750 GeV Diphoton excess in a radiative seesaw model

Abstract

We investigate a possibility for explaining the recently announced 750 GeV diphoton excess by the ATLAS and CMS experiments at the CERN Large Hadron Collider in a model with multiple doubly charged particles, that was originally suggested for explaining tiny neutrino masses throug a three-loop effect in a natural way. The enhanced radiatively generated effective coupling of a new singlet scalarSwith diphoton with multiple charged particles in the loop enlarges the production rate ofSinpp→S+Xvia a photon fusion process and also the decay width(S→γ γ )even without assuming a tree-level production mechanism. We provide detailed analysis on the cases with or without allowing mixing betweenSand the standard model Higgs doublet.