IceCube events from heavy DM decays through the right-handed neutrino portal

The recently observed IceCube PeV events could be due to heavy dark matter (DM) decay. In this paper, we propose a simple DM model with extra U(1)(X) gauge symmetry and bridge it with standard model particles through heavy right-handed neutrino. The Dirac fermion DM chi with mass similar to 5PeV can dominantly decay into a dark Higgs (phi), the SM Higgs (h) and a neutrino (nu). If the lifetime of chi is similar to O(10(28)) s, the resulting neutrino flux can fit data consistently. The neutrino flux from chi ->phi h nu in our model is softer than the one predicted from chi ->nu h, for example. We also discuss a possible mechanism to produce DM with the right relic abundance. (C) 2015 The Authors. Published by Elsevier B.V.