IceCube PeV Neutrino Events from the Decay of Superheavy Dark Matter;an
  Analysis
  Considering the ultrahigh energy (UHE) neutrino events reported by IceCube in
the PeV regime to have originated from the decay of superheavy dark matter, the
IceCube UHE neutrino events are analysed and the best fit values of the two
parameters namely the mass of the superheavy dark matter and its decay lifetime
are obtained. The theoretical astrophysical flux is also included in
theanalysis. We find that while the neutrino events in the energy range $\sim$
60 TeV-$\sim$ 120 TeV appears to have astrophysical origin, the events in the
energy range $\sim 1.2 \times 10^5$ GeV - $\sim 5 \times 10^7$ GeV can be well
described from the superheavy dark matter decay hypothesis. We also find that
although hadronic decay channel of the superheavy dark matter can well explain
the events in the energy range $\sim 1.2 \times 10^5$ GeV - $\sim 5 \times
10^6$ GeV, the higher energy regime higher than this range can be addressed
only when the leptonic decay channel is considered.
