Inflation with low reheat temperature and cosmological constraint on stable charged massive particles

Abundance of stable charged massive particles (CHAMPs) is severely constrained by their searches inside sea water. We examine whether inflation with low reheat temperature can sufficiently dilute the abundance to evade this severe bound on CHAMPs, by taking into account their production and annihilation in a plasma during reheating phase. We argue that the abundance of the CHAMPs with mass less than 1 TeV will exceed the experimental bound, ruling out these CHAMPs, especially the possibility of the superpartner of tau lepton as the stable lightest superparticle. On the other hand, it is found that the CHAMP much heavier than 1 TeV can survive the bound, if the reheat temperature is low enough.