Abstract
We carry out a detailed study of the confinement phase transition in a dark sector with a $SU(N)$ gauge group and a single generation of dark heavy quark. We focus on heavy enough quarks such that their abundance freezes out before the phase transition and the phase transition is of first-order. We find that during this phase transition the quarks are trapped inside contracting pockets of the deconfined phase and are compressed enough to interact at a significant rate, giving rise to a second stage of annihilation that can dramatically change the resulting dark matter abundance. As a result, the dark matter can be heavier than the often-quoted unitarity bound of $\sim100~$TeV. Our findings are almost completely independent of the details of the portal between the dark sector and the Standard Model. We comment briefly on possible signals of such a sector. Our main findings are summarized in a companion letter, while here we provide further details on different parts of the calculation.
Highlights
The cosmic abundance of dark matter (DM) is comparable to the abundance of Standard Model (SM) particles up to an Oð1Þ factor [1]
We find a dramatic suppression in the final abundance thanks to this phenomenon, which points to much heavier dark matter parameter space than was previously thought
We assumed that the dark sector under study is a confining SUð3Þ gauge theory with a single generation of heavy fermions; we assumed a portal exists between the sectors that keeps them in kinetic equilibrium and allows the glueballs and mesons to decay to the SM
Summary
The cosmic abundance of dark matter (DM) is comparable to the abundance of Standard Model (SM) particles up to an Oð1Þ factor [1]. [44,45,46,47],1 but the effects of the phase transition on the relic abundance of dark matter in confining dark sector models are mostly unexplored, with the exception of a recent study of dark sectors with only light quarks (mq ≤ Λ) [51]. This model allows the DM candidate to be heavier than the perturbative unitarity bound on weakly interacting massive particles (WIMPs), despite being thermal Since this second stage of annihilation is controlled by the dynamics within the dark sector and not the interaction between the dark sector and SM, our results are largely independent of the portal to the SM. For a more condensed discussion than what follows, see the companion paper Ref. [57]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
