Direct search constraints on very heavy dark skyrmions

Abstract

Abstract In the standard dark matter creation scenario, dark matter arises from freeze-out due to decoupling from the thermal heat bath in the early universe. On the other hand, topological solitons can also emerge during phase transitions through the Kibble–Zurek mechanism or through bubble nucleation. In particular, Murayama and Shu found that the Kibble–Zurek mechanism can produce topological defects up to about 10 PeV, and Bramante et al. had recently pointed out that direct search constraints can be extrapolated to very large masses. Motivated by these observations, we examine direct search constraints for PeV scale dark skyrmions with a Higgs portal coupling to baryons. We find abundance constraints on the combination $$g_V^2M_S$$gV2MS of Skyrme coupling $$g_V$$gV and skyrmion mass $$M_S$$MS. We also find that extrapolation of the direct search constraints from XENON1T to very high masses constrains the combination $$g_{wh}/g_V^4$$gwh/gV4 as a function of $$M_S$$MS, where $$g_{wh}$$gwh is the Higgs portal coupling of the dark skyrmions.