Baryogenesis via Particle-Antiparticle Oscillations

TL;DR

This paper explores how particle-antiparticle oscillations with CP violation in the early Universe can generate baryon asymmetry, focusing on a specific supersymmetric model with bino oscillations and baryon-number violation.

Contribution

It demonstrates that baryon asymmetry can be produced through out-of-equilibrium decays of oscillating particles in a $U(1)_R$-symmetric SUSY model, a novel mechanism for baryogenesis.

Findings

Bino-antibino oscillations can generate the observed baryon asymmetry.

CP violation enhances baryon asymmetry production.

Baryon-number-violating decays are crucial for the mechanism.

Abstract

CP violation, which is crucial for producing the baryon asymmetry of the Universe, is enhanced in particle-antiparticle oscillations. We study particle-antiparticle oscillations (of a particle with mass O(100 GeV)) with CP violation in the early Universe in the presence of interactions with O(ab-fb) cross-sections. We show that, if baryon-number-violating interactions exist, a baryon asymmetry can be produced via out-of-equilibrium decays of oscillating particles. As a concrete example we study a $U(1)_R$-symmetric, R-parity-violating SUSY model with pseudo-Dirac gauginos, which undergo particle-antiparticle oscillations. Taking bino to be the lightest $U(1)_R$-symmetric particle, and assuming it decays via baryon-number-violating interactions, we show that bino-antibino oscillations can produce the baryon asymmetry of the Universe.