  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.
