$CP$ 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 $O(100\mathrm{GeV})$] with $CP$ violation in the early Universe in the presence of interactions with $O(\mathrm{ab}\text{−}\mathrm{fb})$ 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 supersymmetry 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.

• Received 14 April 2016

DOI:https://doi.org/10.1103/PhysRevD.93.123528