The favored tests of CP violation in B meson decays give sin 2α and sin 2β, where α and β are angles in the unitarity triangle relating the Kobayashi–Maskawa matrix elements. In the classic B Factory experiment sin 2α or sin 2β is obtained by observing a time dependent CP violating asymmetry in the decay of tagged B0, [Formula: see text] pairs, mediated by [Formula: see text] mixing. The same measurement can be performed at a symmetric energy collider operating at the ϒ (4S) resonance, given sufficient luminosity and vertex resolution. That is, provided the vertical spread of the beam at the interaction point is small, for two-event subclasses the centroid separation in measurements of the observed midpoint between the heights of the two decay vertices is a good statistical estimator for the CP violation parameter sin 2α or sin 2β. With a typical detector the number of events needed is about three times what an asymmetric B Factory would require for the same accuracy.
Exploring CP-Violation Through B Decays
