STUDY OF THE DECAYS D-]K-PI-PI-EV AND D-]K-STAR-PI-EV

UNIV SAO PAULO SAO PAULO BRAZIL UNIV TORONTO TORONTO M5S 1A7 ONTARIO C ANADA UNIV MISSISSIPPI OXFORD MS 38677 YALE UNIV NEW HAVEN CT 06511 We have searched for the exclusive semileptonic decay modes D+ --> K-pi- pi-eBAR+ nu(e) and D+ --> KBAR pi-e+ nu(e) in the data from the Fermi lab photoproduction experiment E691. With good sensitivity, we observe no signals in the channels D+ --> K- pi+pi(0)e+ nu(e) and D+ --> K0BA R pi+pi-e+ nu(e), and set upper limits of B(D+ --> all KBAR pi-e+ nu( e)) < 1.2% and B(D+ --> all K-pi-pi-eBAR+ nu(e)) < 0.9%, at the 90% co nfidence level. (For these limits we use isospin invariance to extract limits which include all charge states.) These modes are expected to be the most common semileptonic decays next to the dominant Ke+BAR v(e ) and KE+BAR v(e), but the observed limits represent a small fraction of the inclusive semileptonic branching ratio of (17.0 +/- 1.9 +/- 1. 7)%.