Studies of CP Violation in Rare KL Decays

Historically, the pi pi decays of the KS and the KL have provided the only window on the phenomenon of CP violation. But more recently, considerable attention has focussed on the possiblility of extracting the value of the Wolfenstein parameter eta from a measurement of CP-violating amplitudes for a variety of rare KL decays. Because the KL is so long-lived, it may be possible to observe the effects of even highly suppressed CP-violating decay diagrams within the Standard Model, or to detect very rare KL decays forbidden by the Standard Model or inconsistent with its predictions. Three of the decays on which we plan to concentrate are: