A pr 2 00 6 1 COMPOSITE DARK MATTER AND ITS CHARGED CONSTITUENTS (original) (raw)

Stable charged heavy leptons and quarks can exist and hide in elusive atoms, bound by Coulomb attraction and playing the role of dark matter. However, in the expanding Universe it is not possible to recombine all the charged particles into such atoms, and the positively charged particles, which escape this recombination, bind with electrons in atoms of anomalous isotopes with pregalactic abundance, exceeding substantially the terrestrial upper limits. This abundance can not be reduced in the dense matter bodies, if negatively charged particles have charge −1. Therefore composite dark matter can involve only negatively charged particles with charge −2 , while stable heavy particles with charge −1 should be excluded. Realistic scenarios of composite dark matter, avoiding this problem of anomalous isotope overproduction , inevitably predict the existence of primordial " atoms " , in which primordial helium traps all the free negatively charged heavy constituents with charge −...