Confronting a New Three-loop Seesaw Model with the 750 GeV Diphoton   Excess
  We propose a new type of radiative neutrino model with a local hidden $U(1)$ symmetry, in which neutrino masses are induced at the three loop level, and discuss the muon anomalous magnetic moment, and dark matter candidates therein. By allowing the hypercharges larger than 3/2 for new fields that contribute to the neutrino masses and making them decay into the standard model fields appropriately, we introduce a lot of new particles with multiple electrical charges in a natural manner. As a by-product, we can accommodate the 750 GeV diphoton excess depending on the hypercharge quantum numbers of new fields responsible for the neutrino masses at the three loop level. 
P. Ko, Takaaki Nomura, Hiroshi Okada, Yuta Orikasa
hep-ph