Interpretation of 750 GeV diphoton excess at LHC in singlet extension of color-octet neutrino mass model

Abstract

We propose that the possible 750 GeVdiphoton excess can be explained in the color-octet neutrino mass model extended with a scalar singlet $$\Phi $$ . The model generally contains $$N_s$$ species of color-octet, electroweak doublet scalars S and $$N_f$$ species of color-octet, electroweak triplet $$\chi $$ or singlet $$\rho $$ fermions. While both scalars and fermions contribute to the production of $$\Phi $$ through gluon fusion, only the charged members induce the diphoton decay of $$\Phi $$ . The diphoton rate can be significantly enhanced due to interference between the scalar and fermion loops. We show that the diphoton cross section can be from 3 to 10 fb for $$\mathcal {O}(\mathrm{TeV})$$ color-octet particles while evading all current LHC limits.