String Fragmentation in Supercooled Confinement and Implications for Dark Matter

Understand

A strongly-coupled sector can feature a supercooled confinement transition in the early universe.

• We point out that, when fundamental quanta of the strong sector are swept into expanding bubbles of the confined phase, the distance between them is large compared to the confinement scale.
• We suggest a modelling of the subsequent dynamics and find that the flux linking the fundamental quanta deforms and stretches towards the wall, producing an enhanced number of composite states upon string fragmentation.
• The composite states are highly boosted in the plasma frame, which leads to additional particle production through the subsequent deep inelastic scattering.