| Analyses of several charmed baryons decaying to L+c are presented. The data for these analyses were collected by FOCUS, Fermilab Experiment E831. FOCUS is a high statistics charm photoproduction experiment and accumulated data during the 1996--1997 Fermilab Fixed Target run.; In an analysis of the decays Sc→L+cp +/- we measure the Sc-L+c, S++c-S0c , and S+c-S0c mass differences. We find mS0c-mL +c = 167.54 +/- 0.19 +/- 0.34 MeV/c 2, mS++c-mL +c = 167.59 +/- 0.20 +/- 0.27 MeV/c 2, and mS++c-mS 0c = 0.05 +/- 0.28 +/- 0.09 MeV/c2 . In an analysis of the decay S+c→L+ cp0 we find mS+c-mL +c = 168.03 +/- 1.01 +/- 0.30 MeV/c 2 and mS+c-mS 0c = 0.49 +/- 1.03 +/- 0.45 MeV/c2 . These results are obtained with a sample of 362 +/- 36 S0c→L+ cp- decays, 118 +/- 40 S+c→L+ cp0 decays, and 487 +/- 41 S++c→L+ cp+ decays. The results with charged pions are improvements on the best available measurements.; Using a cleaner analysis of Sc→L+cp +/- decays, we measure the widths of S0c and S++c . We find GS0c =2.58+/-0.79+0.51-0.55 MeV/c2 and GS++c =2.53+/-0.77+0.51-0.56 MeV/c2. These results are obtained with a sample of 425 +/- 55 S0c→L+ cp- decays and 540 +/- 59 S++c→L+ cp+ decays. There are no published measurements of the Sc widths.; We also report on the observation of two excited charm baryon resonances decaying to L+cp+/- . These states are interpreted as the S*0c and S*++c with I&parl0;JP&parr0;=1&parl0;32 +&parr0; . We obtain preliminary measurements of the properties of these states of mS*0c-mL +c = 232.7 +/- 1.2 MeV/c2, G&parl0;S*0c&parr0; = 9.4 +/- 3.7 MeV/c2, mS*++c-mL +c = 234.2 +/- 1.5 MeV/c2, and G&parl0;S*0c&parr0; = 23.6 +/- 4.5 MeV/c2. These measurements are compatible with the only previous observation, but no attempt is made to optimize statistical errors or determine systematic errors.; Finally, we report on a search for the doubly charmed baryons X+cc and X++cc in the decay modes Xcc→L+c K-np . No compelling evidence for the existence of doubly charmed baryon states is observed. |
