Supercool exit: Gravitational waves from QCD-triggered conformal symmetry breaking

Understand

Classically conformal Standard Model extensions predict an intriguing thermal history of the early universe.

• In contrast to the common paradigm, the onset of the electroweak phase transition can be significantly delayed while the universe undergoes a period of thermal inflation.
• Then, a first-order chiral phase transition could not only trigger electroweak symmetry breaking but also initiate the exit from supercooling.
• To study the dynamics of this scenario, we focus on low-energy quark-based QCD effective models that exhibit a first-order transition.