On Baryogenesis and $n \bar n$-Oscillations

TL;DR

This paper explores a model with color sextet scalars that violate baryon number, linking neutron-antineutron oscillations to baryogenesis, and analyzes experimental prospects and constraints through numerical solutions of Boltzmann equations.

Contribution

It introduces a baryon number violating model with specific scalar fields that connects neutron oscillations to baryogenesis and provides numerical constraints on parameters.

Findings

Successful high-scale baryogenesis imposes restrictions on model parameters.

Parameter regions are identified where the model can be tested by experiments.

Numerical solutions show significant washout effects due to color charges.

Abstract

We study a simple model where color sextet scalars violate baryon number at tree level but do not give rise to proton decay. In particular, we include one light and two heavy sextets with $\Delta B=2$ baryon number violating interactions that induce neutron anti-neutron oscillations. This setup also suggests an intimate connection to the generation of the observed baryon asymmetry in the Universe via the out of equilibrium decay of the heavy sextet scalars at around $10^{14}$ GeV. The large $SU(3)$-color charges of the scalar fields involved in generating the baryon asymmetry motivate us to study potentially significant washout effects. We numerically solve a set of Boltzmann evolution equations and find restrictions on the available model parameters imposed by successful high scale baryogenesis. Combining our new numerical results for baryogenesis with $n\bar n$-oscillation predictions and collider limits on the light sextet, we identify parameter regions where this model can be probed by current and future experiments.