Observation of the singly Cabibbo-suppressed decay Λc+ → ς-K+π+

Journal
Physical Review D
ISSN
24700010
Date Issued
2024-04-01
Author(s)
Ablikim, M.
Achasov, M. N.
Adlarson, P.
Ai, X. C.
Aliberti, R.
Amoroso, A.
An, M. R.
An, Q.
Bai, Y.
Bakina, O.
Balossino, I.
Ban, Y.
Batozskaya, V.
Begzsuren, K.
Berger, N.
Berlowski, M.
Bertani, M.
Bettoni, D.
Bianchi, F.
Bianco, E.
Bortone, A.
Boyko, I.
Briere, R. A.
Brueggemann, A.
Cai, H.
Cai, X.
Calcaterra, A.
Cao, G. F.
Cao, N.
Cetin, S. A.
Chang, J. F.
Chang, T. T.
Chang, W. L.
Che, G. R.
Chelkov, G.
Chen, C.
Chen, Chao
Chen, G.
Chen, H. S.
Chen, M. L.
Chen, S. J.
Chen, S. M.
Chen, T.
Chen, X. R.
Chen, X. T.
Chen, Y. B.
Chen, Y. Q.
Chen, Z. J.
Cheng, W. S.
Choi, S. K.
Chu, X.
Cibinetto, G.
Coen, S. C.
Cossio, F.
Cui, J. J.
Dai, H. L.
Dai, J. P.
Dbeyssi, A.
De Boer, R. E.
Dedovich, D.
Deng, Z. Y.
Denig, A.
Denysenko, I.
Destefanis, M.
De Mori, F.
Ding, B.
Ding, X. X.
Ding, Y.
Ding, Y.
Dong, J.
Dong, L. Y.
Dong, M. Y.
Dong, X.
Du, M. C.
Du, S. X.
Duan, Z. H.
Egorov, P.
Fan, Y. H.Y.
Fan, Y. L.
Fang, J.
Fang, S. S.
Fang, W. X.
Fang, Y.
Farinelli, R.
Fava, L.
Feldbauer, F.
Felici, G.
Feng, C. Q.
Feng, J. H.
Fischer, K.
Fritsch, M.
Fritzsch, C.
Fu, C. D.
Fu, J. L.
Fu, Y. W.
Gao, H.
Gao, Y. N.
Gao, Yang
Garbolino, S.
Garzia, I.
DOI
Abstract
The singly Cabibbo-suppressed decay Λc+→ς-K+π+ is observed for the first time with a statistical significance of 5.4σ by using 4.5 fb-1 of e+e- collision data collected at center-of-mass energies between 4.600 and 4.699 GeV with the BESIII detector at BEPCII. The absolute branching fraction of Λc+→ς-K+π+ is measured to be (3.8±1.2stat±0.2syst)×10-4 in a model-independent approach. This is the first observation of a Cabibbo-suppressed Λc+ decay involving ς- in the final state. The ratio of branching fractions between Λc+→ς-K+π+ and the Cabibbo-favored decay Λc+→ς-π+π+ is observed to be (0.4±0.1)sc2, where scsinθc=0.2248 with θc the Cabibbo mixing angle.
Volume
109