Search for $\ddot{I}{€}^0\to \hat{I}{½}_{\hat{I}}¼\bar{\hat{I}}{½}_{\hat{I}}¼$ Decay in LSND

Abstract

We observe a net beam-excess of $8.7\pm 6.3$ (stat) $\pm 2.4$ (syst) events, above 160 MeV, resulting from the charged-current reaction of $\hat{I}{½}_{\hat{I}}¼$ and/or $\bar{\hat{I}}{½}_{\hat{I}}¼$ on C and H in the LSND detector. No beam related muon background is expected in this energy regime. Within an analysis framework of $\ddot{I}{€}^0\to \hat{I}{½}_{\hat{I}}¼\bar{\hat{I}}{½}_{\hat{I}}¼$, we set a direct upper limit for this branching ratio of $\hat{I}“(\ddot{I}{€}^0\to \hat{I}{½}_{\hat{I}}¼\bar{\hat{I}}{½}_{\hat{I}}¼)/\hat{I}“(\ddot{I}{€}^0\to all)<1.6\times 10^{-6}$ at 90% confidence level.

4 pages, 4 figures