First measurement of the Λ c + $$ {\Lambda}_c^{+} $$ → pη′ decay

• Published in: The journal of high energy physics 2022-03, Vol.2022 (3), p.1-15
• Main Authors: The BELLE collaboration, S. X. Li, J. X. Cui, C. P. Shen, I. Adachi, H. Aihara, S. Al Said, D. M. Asner, H. Atmacan, T. Aushev, R. Ayad, V. Babu, P. Behera, K. Belous, M. Bessner, V. Bhardwaj, B. Bhuyan, T. Bilka, D. Bodrov, G. Bonvicini, J. Borah, A. Bozek, M. Bračko, P. Branchini, T. E. Browder, A. Budano, M. Campajola, D. Červenkov, M.-C. Chang, P. Chang, V. Chekelian, A. Chen, B. G. Cheon, K. Chilikin, H. E. Cho, K. Cho, S.-J. Cho, S.-K. Choi, Y. Choi, S. Choudhury, D. Cinabro, S. Cunliffe, S. Das, N. Dash, G. De Nardo, G. De Pietro, R. Dhamija, F. Di Capua, Z. Doležal, T. V. Dong, D. Epifanov, T. Ferber, D. Ferlewicz, B. G. Fulsom, R. Garg, V. Gaur, N. Gabyshev, A. Giri, P. Goldenzweig, B. Golob, E. Graziani, T. Gu, T. Hara, K. Hayasaka, H. Hayashii, W.-S. Hou, K. Inami, A. Ishikawa, M. Iwasaki, Y. Iwasaki, W. W. Jacobs, E.-J. Jang, S. Jia, Y. Jin, K. K. Joo, J. Kahn, A. B. Kaliyar, K. H. Kang, Y. Kato, T. Kawasaki, H. Kichimi, C. Kiesling, C. H. Kim, D. Y. Kim, Y.-K. Kim, K. Kinoshita, P. Kodyš, T. Konno, A. Korobov, S. Korpar, E. Kovalenko, P. Križan, R. Kroeger, P. Krokovny, M. Kumar, R. Kumar, K. Kumara, Y.-J. Kwon, T. Lam, M. Laurenza
• Format: Article
• Language: English
• Subjects: Branching fraction; Charm Physics; e +-e − Experiments; Particle and Resonance Production
• ISSN: 1029-8479
• DOI: 10.1007/JHEP03(2022)090

Abstract We present the first measurement of the branching fraction of the singly Cabibbo-suppressed (SCS) decay Λ c + $$ {\Lambda}_c^{+} $$ → pη′ with η′ → ηπ + π − , using a data sample corresponding to an integrated luminosity of 981 fb −1, collected by the Belle detector at the KEKB e + e − asymmetric-energy collider. A significant Λ c + $$ {\Lambda}_c^{+} $$ → pη′ signal is observed for the first time with a signal significance of 5.4σ. The relative branching fraction with respect to the normalization mode Λ c + $$ {\Lambda}_c^{+} $$ → pK − π + is measured to be B Λ c + → pη ′ B Λ c + → pK − π + = 7.54 ± 1.32 ± 0.73 × 10 − 3 , $$ \frac{\mathcal{B}\left({\Lambda}_c^{+}\to p\eta^{\prime}\right)}{\mathcal{B}\left({\Lambda}_c^{+}\to {pK}^{-}{\pi}^{+}\right)}=\left(7.54\pm 1.32\pm 0.73\right)\times {10}^{-3}, $$ where the uncertainties are statistical and systematic, respectively. Using the world-average value of B Λ c + → pK − π + $$ \mathcal{B}\left({\Lambda}_c^{+}\to {pK}^{-}{\pi}^{+}\right) $$ = (6.28 ± 0.32) × 10 −2, we obtain B Λ c + → pη ′ = 4.73 ± 0.82 ± 0.46 ± 0.24 × 10 − 4 , $$ \mathcal{B}\left({\Lambda}_c^{+}\to p\eta^{\prime}\right)=\left(4.73\pm 0.82\pm 0.46\pm 0.24\right)\times {10}^{-4}, $$ where the uncertainties are statistical, systematic, and from B Λ c + → pK − π + $$ \mathcal{B}\left({\Lambda}_c^{+}\to {pK}^{-}{\pi}^{+}\right) $$ , respectively.