We report the first observation of the decay Λc+→pK+π- using a 980 fb-1 data sample collected by the Belle detector at the KEKB asymmetric-energy e+e- collider. This is the first observation of a doubly Cabibbo-suppressed decay of a charmed baryon. We measure the branching ratio of this decay with respect to its Cabibbo-favored counterpart to be B(Λc+→pK+π-)/B(Λc+→pK-π+)=(2.35±0.27±0.21)×10-3, where the uncertainties are statistical and systematic, respectively.
Bibliographical noteFunding Information:
We thank the KEKB group for excellent operation of the accelerator; the KEK cryogenics group for efficient solenoid operations; and the KEK computer group, the NII, and PNNL/EMSL for valuable computing and SINET4 network support. We acknowledge support from MEXT, JSPS, and Nagoya's TLPRC (Japan); ARC and DIISR (Australia); FWF (Austria); NSFC and CCEPP (China); MSMT (Czechia); CZF, DFG, and VS (Germany); DST (India); INFN (Italy); MOE, MSIP, NRF, GSDC of KISTI, and BK21Plus (Korea); MNiSW and NCN (Poland); MES and RFAAE (Russia); ARRS (Slovenia); IKERBASQUE and UPV/EHU (Spain); SNSF (Switzerland); NSC and MOE (Taiwan); and DOE and NSF (USA).
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)