Resolving phenomenological problems with strongly-interacting-massive-particle models with dark vector resonances

Abstract

We consider a light dark matter candidate that is produced by the freeze-out mechanism with $3\ensuremath{\rightarrow}2$ annihilations, the so-called strongly interacting massive particles (SIMPs). SIMPs are identified as dark pions in dark chiral perturbation theory (ChPT) in which both light mass and strong coupling needed for SIMPs can be realized by strong dynamics. In QCD-like theories with $SU(3{)}_{L}\ifmmode\times\else\texttimes\fi{}SU(3{)}_{R}/SU(3{)}_{V}$ flavor symmetry, including dark vector mesons in the hidden local symmetry scheme, we illustrate that dark vector mesons unitarize the dark ChPT efficiently, thus determining the correct relic density condition within the validity of the dark ChPT.