The Standard Model CP Violation is Enough

TL;DR

This paper proposes a novel baryogenesis mechanism using only Standard Model CP violation, enhanced by dark sector dynamics, capable of explaining the universe's baryon asymmetry and producing detectable gravitational waves.

Contribution

It introduces Mesogenesis with a Morphing Mediator, a new model that achieves baryogenesis solely through Standard Model CP violation and dark sector interactions.

Findings

The mechanism can generate the observed baryon asymmetry.

Dark sector dynamics produce gravitational waves detectable by Pulsar Timing Arrays.

The model evades current collider constraints while enhancing baryon production.

Abstract

Is the Standard Model Charge-Parity (CP) violation ever enough to generate the observed baryon asymmetry? Yes! We introduce a mechanism of baryogenesis (and dark matter production) that can generate the entire observed baryon asymmetry of the Universe using $\textit{only}$ the CP violation within Standard Model systems -- a f\^ete which no other mechanism currently proposed can achieve. Baryogenesis proceeds through a Mesogenesis scenario but with well motivated additional dark sector dynamics: a $\textit{morphon}$ field generates present day mass contributions for the particle mediating the decay responsible for baryogenesis. The effect is an enhancement of baryon production whilst evading present day collider constraints. The CP violation comes entirely from Standard Model contributions to neutral meson systems. Meanwhile, the dark dynamics generate gravitational waves that may be searched for with current and upcoming Pulsar Timing Arrays, as we demonstrate with an example. This mechanism, $\textit{Mesogenesis with a Morphing Mediator}$, motivates probing a new parameter space as well as improving the sensitivity of existing Mesogenesis searches at hadron and electron colliders.