  We investigate a possibility for explaining the recently announced 750\,GeV
diphoton excess by the ATLAS and the CMS experiments at the CERN LHC in a model
with multiple doubly charged particles, which was originally suggested for
explaining tiny neutrino masses through a three-loop effect in a natural way.
The enhanced radiatively generated effective coupling of a new singlet scalar
$S$ with diphoton with multiple charged particles in the loop enlarges the
production rate of $S$ in $pp\to S+X$ via photon fusion process and also the
decay width $\Gamma(S\to \gamma\gamma)$ even without assuming a tree level
production mechanism. We provide detailed analysis on the cases with or without
allowing the mixing between $S$ and the standard model Higgs doublet.

High Energy Physics - Phenomenology