Matter–Antimatter Asymmetries from Particle–Unparticle Transitions

Majid Ekhterachian

EPFL, Lausanne

Tue, May. 09th 2023, 14:00-15:00

Salle Claude Itzykson, Bât. 774, Orme des Merisiers

I will discuss a mechanism for baryogenesis from out of equilibrium decays of particles into (unparticle) states of a nearly conformal sector, applicable to composite Higgs model. The generation and evolution of the slowly varying charge and particle number densities can be described by a set “Boltzmann equations” whose coefficients can be expressed in terms of CFT correlation functions. I will apply this formalism to high scale leptogenesis in composite Higgs models and evaluate the asymmetry generation before the confining phase transition (PT) during which the composite Higgs is formed. I will then discuss how the PT may be analyzed and consider its effects on the matter abundances. The cosmological PT in the minimal models tend to complete only after a large period of supercooling, potentially resulting in excessive dilution of matter abundances. However, I will show how generic modification of the minimal models can result in a much faster completion of the PT, allowing for compatibility with baryogenesis before the PT.

Contact : Gabriele
RIGO