First observation of the exclusive decaysΛc+→Λπ+π+π−π0andΛc+→Λωπ+

D Cronin-Hennessy,B Gittelman,R Ammar,B K Heltsley,S B Athar,A Magerkurth,H Stoeck,R Poling,C J Stepaniak,R Nandakumar,V V Frolov,H Mahlke-Krüger,T Hart,C Gwon,H Schwarthoff,J Urheim,V Pavlunin,B I Eisenstein,K Honscheid,M Weinberger,D Urner,H Muramatsu,C Plager,C S Park,R Ehrlich,G Bonvicini,J B Thayer,S W Gray,A J Sadoff,V Boisvert,T Wilksen,D L Kreinick,S Blusk,N B Mistry,K K Gan,G C Moneti,N Lowrey,M R Shepherd,E Von Toerne,D L Hartill,E Nordberg,G D Gollin,L Breva-Newell,W Park,V Potlia,M Dubrovin,D Cinabro,J Kandaswamy,K Benslama,P S Drell,E I Shibata,H Kagan,E H Thorndike,K Bukin,R A Briere,K K Seth,Z Metreveli,V Savinov,E Dambasuren,K W Edwards,S P Pappas,A Bornheim,P Skubic,J W Hinson,J E Duboscq,D Hufnagel,S J Richichi,D Riley,D Peterson,D T Gong,T E Coan,M M Zoeller,I Karliner,F Liu,S Ahmed,T K Pedlar,R Mountain,J J Thaler,C Boulahouache,R S Galik,L Hsu,A H Mahmood,A L Lyon,S E Csorna,J Pivarski,G Tatishvili,M S Alam,C Sedlack,D G Cassel,Y Maravin,S Dytman ,K M Ecklund,James S Williams ,E A Eckhart ,J Yelton,A Warburton,A Tomaradze,M Selen,J Alexander ,L Gibbons,G P Chen,T Skwarnicki,P Avery,W Sun ,D Besson,A Shapiro,Steven Mcgee ,E Lipeles,T O Meyer,S Z Li,J Lee,Y Kubota,X Zhao,S Nam,R Kass,M Artuso,D H Miller,F R Wappler ,K Arms,M Saleem,Y S Gao,J G Thayer,A J Weinstein,S Chen,J Muêller ,P Zweber,J R Patterson,I Dankó ,S Anderson,H Vogel,T Ferguson,H Severini,J C Wang,R Stroynowski,C D Jones,S Stone,N Adam ,L Jian,J Ernst,K Berkelman,A Smith,I P J Shipsey

doi:10.1103/physrevd.67.012001

Abstract

Using data recorded by the CLEO III detector at CESR, we report on the first measurements of the branching fractions for decays of the Lambda_c^+ charmed baryon into (Lambda pi+ pi+ pi- pi0) and (Lambda omega pi+). All rates are measured with respect to the p K- pi+ decay mode. The relative branching fractions are 0.39 +- 0.09(stat.) +- 0.09(syst.) and 0.24 +- 0.06(stat.) +- 0.06(syst.) for the (Lambda pi+ pi+ pi- pi0) and (Lambda omega pi+) modes, respectively. The data also suggest decays of the Lambda_c^+ via (Lambda eta pi+, eta --> pi+ pi- pi0) with a rate which is consistent with previous measurements of the branching fraction of Lambda_c^+ to (Lambda eta pi+, eta --> gamma gamma). The measurements indicate that the omega and eta sub-modes comprise 87+-13% of the (Lambda pi+ pi+ pi- pi0) final state. We set an upper limit on the contribution from non-omega and non-eta modes of 0.13 at the 90% confidence level.

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