  The electroweak sphaleron process breaks the baryon number conservation
within the realms of the Standard Model of particle physics (SM). Recently, it
is pointed out that its decoupling may provide the out-of-equilibrium condition
required for baryogenesis. In this paper, we study such a scenario taking into
account the baryon-number wash-out effect of the sphaleron itself to improve
the estimate. We clarify the amount of CP violation required for this scenario
to explain the observed asymmetry.
