Electroweak baryogenesis in the ℤ₃ -invariant NMSSM

We calculate the baryon asymmetry of the Universe in the ℤ₃-invariant Next-to-Minimal Supersymmetric Standard Model where the interactions of the singlino provide the necessary source of charge and parity violation. Using the closed time path formalism, we derive and solve transport equations for the cases where the singlet acquires a vacuum expectation value (VEV) before and during the electroweak phase transition. We perform a detailed scan to show how the baryon asymmetry varies throughout the relevant parameter space. Our results show that the case where the singlet acquires a VEV during the electroweak phase transition typically generates a larger baryon asymmetry, although we expect that the case where the singlet acquires a VEV first is far more common for any model in which parameters unify at a high scale. Finally, we examine the dependence of the baryon asymmetry on the three-body interactions involving gauge singlets.