The Cosmic QCD Phase Transition, Quasi-baryonic Dark Matter and Massive Compact Halo Objects

Abstract

We propose that the cold dark matter (CDM) is composed entirely of quark matter, arising from a cosmic quark-hadron transition. We denote this phase as "quasibaryonic", distinct from the usual baryons. We show that compact gravitational lenses, with masses around 0.5 (M_{\odot}), could have evolved out of the quasibaryonic CDM.