“Eight solid light-years of lead…is the thickness of that metal in which you would need to encase yourself if you wanted to keep from being touched by neutrinos.” -Michael Chabon
When it comes to dark matter, the most commonly considered candidates are WIMPs, or Weakly-Interacting Massive Particles. But with the failure of the LHC to turn up anything compelling at the ~100 GeV scale, or any robust hints of a new particle, for that matter, it might be time to consider another possible solution at much higher energies: a heavy, right-handed neutrino.
Neutrinos are all left-handed (and antineutrinos are all right-handed), and have extremely small but non-zero masses, likely due to a process known as the See-Saw Mechanism. If this is the case, there should be right-handed neutrinos (and left-handed antineutrinos) that have tremendous masses: more than a billion times as heavy as the other Standard Model particles. While often overlooked, these “WIMPzillas” could make up 100% of the missing dark matter in the Universe, and be the solution to one of nature’s greatest mysteries.