Future Kaon Programs at BNL , FNAL 1

Future kaon decay programs at BNL and FNAL are discussed. The primary focus of these programs is the measurement of the golden modes, K • L → π • νν and K + → π + νν. The observation of K + → π + νν by E787 at BNL is the first step in a series of measurements which will completely determine the unitarity triangle within the kaon system. The next step after E787 in the measurement of B(K + → π + νν) will be the E949 experiment at BNL that is currently under construction. This experiment, building on the experience of E787 and making use of the intense AGS proton beam, is scheduled to run in FY01–03 and to observe O(10) SM events with a small and well-understood background. The proposed CKM experiment at FNAL would take the next step, using a decay-in-flight technique and a 22 GeV/c RF-separated kaon beam from the Main Injector, to observe O(100) SM events. At the same time, two concepts for the measurement of B(K • L → π • νν) have been developed. One of these, building on the experience of KTeV with a 'pencil' K L beam, has been proposed at FNAL as KAMI. The other, with a measurement of the kaon momentum in a large angle K L beam derived from a bunched proton beam, has been proposed at BNL as KOPIO.