Abstract
An upper limit on the branching ratio for the decay is set at 7.5 × (90% C.L.) using the kinematic region above the peak. When combined with our result from below the peak, we obtain the limit 5.2 × . An upper limit of 1.7 × is also found on the branching ratio for decays of the form where is any massless, weakly interacting neutral particle. Limits are also set for cases where .
- Received 16 October 1992
DOI:https://doi.org/10.1103/PhysRevLett.70.2521
©1993 American Physical Society