ARE THERE CP-VIOLATING PROCESSES IN THE STANDARD MODEL WITHOUT LOOP CORRECTIONS?

Abstract

In an effort to find new CP-violating phenomena in the Standard Model, we present a new type of CP asymmetries which have interesting theoretical features. We investigate the possibility of CP nonconservation manifesting itself at Born level. We find that such processes indeed exist provided the reaction under consideration includes two W’s coupled to two different flavors and an additional boson (γ, g, Z0, H0). A second interesting aspect of these phenomena is the property that the CP-violation appears in a scattering process as opposed to that in a decay of a particle. We estimate the values of these CP asymmetries within the Standard Model with three and four generations and show that the effect is, in principle, measurable if the masses of the quarks belonging to the fourth generation are large.