A clean tagged sample can be selected by demanding, in addition, a -meson in an intermediate state. The CLEO collaboration has observed a signal for with a branching ratio of . At LHC-B , we expect to reconstruct dilepton events and hadronic decays , . Even with additional cuts to remove possible background events, one remains with a sensitivity of for . In a study by Bucella et al.
Particle identification is crucial.
The difficulty in measurements of the type discussed here is to ensure a symmetric reconstruction efficiency for charged-conjugate final states to the level of better than . Therefore, reference channels with an expected asymmetry of zero are useful to calibrate the reconstruction efficiencies. The measurement of direct C P -violation at the level currently predicted by the standard model is clearly feasible. The importance of such measurements in testing the consistency of the standard model and searching for new physics cannot be stressed too highly.