An event consistent with the signature expected for the rare kaon decay K+→π+vv¯ has been observed. In the pion momentum region examined, 211 < P < 230MeV/c, the backgrounds are estimated to contribute 0.08 ± 0.03 events. If the event is due to K+→π+vv¯, the branching ratio is 4.2+9.7−3.5 × 10−10.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)