Quark Nugget Dark Matter: No contradictions with neutrino flux constraints

Abstract

It has recently been claimed that dark matter in form of quark nuggets cannot account for more than 20% of the dark matter density. This claim is based on constraints on the neutrino flux in 20-50 MeV range where the sensitivity of underground neutrino detectors such as Super-Kamiokande have their highest signal-to-noise ratio. We argue that this claim depends crucially on the assumption that the annihilation of visible baryons with an antiquark nugget will generate a neutrino spectrum similar to the conventional baryon-antibaryon annihilation spectrum in vacuum. However, this assumption does not hold for the nuggets in a colour superconducting phase where the lightest pseudo Goldstone mesons (the pions and Kaons) have masses in the 20 MeV range, in contrast with conventional pion mass of roughly 140 MeV. Thus, the decay of these light pseudo Goldstone bosons of the CS phase cannot produce highly energetic neutrinos in the 20-50 MeV energy range.