Quark Nugget Dark Matter: No contradictions with neutrino flux constraints

TL;DR

This paper challenges previous constraints on quark nugget dark matter by showing that in a color superconducting phase, the expected neutrino flux is lower, allowing quark nuggets to constitute more than 20% of dark matter.

Contribution

It demonstrates that the neutrino flux constraints are not applicable to quark nuggets in a color superconducting phase due to altered meson masses.

Findings

Neutrino flux from quark nuggets in CS phase is suppressed in 20-50 MeV range.

Color superconductivity changes pseudo Goldstone boson masses, affecting neutrino production.

Quark nuggets could account for more than 20% of dark matter without conflicting with neutrino observations.

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.