Measurement of Singly Cabibbo Suppressed Decays Λ_{c}^{+}→pπ^{+}π^{-} and Λ_{c}^{+}→pK^{+}K^{-}

• Published in: Physical review letters 2016-12, Vol.117 (23), p.232002-232002
• Main Authors: Ablikim, M, Achasov, M N, Ahmed, S, Ai, X C, Albayrak, O, Albrecht, M, Ambrose, D J, Amoroso, A, An, F F, An, Q, Bai, J Z, Bakina, O, Baldini Ferroli, R, Ban, Y, Bennett, D W, Bennett, J V, Berger, N, Bertani, M, Bettoni, D, Bian, J M, Bianchi, F, Boger, E, Boyko, I, Briere, R A, Cai, H, Cai, X, Cakir, O, Calcaterra, A, Cao, G F, Cetin, S A, Chai, J, Chang, J F, Chelkov, G, Chen, G, Chen, H S, Chen, J C, Chen, M L, Chen, S, Chen, S J, Chen, X, Chen, X R, Chen, Y B, Cheng, H P, Chu, X K, Cibinetto, G, Dai, H L, Dai, J P, Dbeyssi, A, Dedovich, D, Deng, Z Y, Denig, A, Denysenko, I, Destefanis, M, De Mori, F, Ding, Y, Dong, C, Dong, J, Dong, L Y, Dong, M Y, Dou, Z L, Du, S X, Duan, P F, Fan, J Z, Fang, J, Fang, S S, Fang, X, Fang, Y, Farinelli, R, Fava, L, Fegan, S, Feldbauer, F, Felici, G, Feng, C Q, Fioravanti, E, Fritsch, M, Fu, C D, Gao, Q, Gao, X L, Gao, Y, Gao, Z, Garzia, I, Goetzen, K, Gong, L, Gong, W X, Gradl, W, Greco, M, Gu, M H, Gu, Y T, Guan, Y H, Guo, A Q, Guo, L B, Guo, R P, Guo, Y, Guo, Y P, Haddadi, Z, Hafner, A, Han, S, Hao, X Q, Harris, F A, He, K L
• Format: Article
• Language: English
• ISSN: 1079-7114
• DOI: 10.1103/PhysRevLett.117.232002

Using 567  pb^{-1} of data collected with the BESIII detector at a center-of-mass energy of sqrt[s]=4.599  GeV, near the Λ_{c}^{+}Λ[over ¯]_{c}^{-} threshold, we study the singly Cabibbo-suppressed decays Λ_{c}^{+}→pπ^{+}π^{-} and Λ_{c}^{+}→pK^{+}K^{-}. By normalizing with respect to the Cabibbo-favored decay Λ_{c}^{+}→pK^{-}π^{+}, we obtain ratios of branching fractions: [B(Λ_{c}^{+}→pπ^{+}π^{-})/B(Λ_{c}^{+}→pK^{-}π^{+})]=(6.70±0.48±0.25)%, [B(Λ_{c}^{+}→pϕ)/B(Λ_{c}^{+}→pK^{-}π^{+})]=(1.81±0.33±0.13)%, and [B(Λ_{c}^{+}→pK^{+}K_{non-ϕ}^{-})/B(Λ_{c}^{+}→pK^{-}π^{+})]=(9.36±2.22±0.71)×10^{-3}, where the uncertainties are statistical and systematic, respectively. The absolute branching fractions are also presented. Among these measurements, the decay Λ_{c}^{+}→pπ^{+}π^{-} is observed for the first time, and the precision of the branching fraction for Λ_{c}^{+}→pK^{+}K_{non-ϕ}^{-} and Λ_{c}^{+}→pϕ is significantly improved.