Measurements of the Branching Fractions of the Semileptonic Decays Ξc0 → Ξ-ℓ+νℓ and the Asymmetry Parameter of Ξc0 → Ξ-π+

Y. B. Li, C. P. Shen, I. Adachi, K. Adamczyk, H. Aihara, S. Al Said, D. M. Asner, T. Aushev, R. Ayad, V. Babu, P. Behera, J. Bennett, M. Bessner, V. Bhardwaj, B. Bhuyan, T. Bilka, J. Biswal, G. Bonvicini, A. Bozek, M. BračkoT. E. Browder, M. Campajola, D. Červenkov, M. C. Chang, A. Chen, B. G. Cheon, K. Chilikin, K. Cho, S. J. Cho, S. K. Choi, Y. Choi, S. Choudhury, D. Cinabro, S. Cunliffe, S. Das, N. Dash, G. De Nardo, R. Dhamija, F. Di Capua, T. V. Dong, S. Eidelman, D. Epifanov, T. Ferber, B. G. Fulsom, R. Garg, V. Gaur, N. Gabyshev, A. Garmash, A. Giri, P. Goldenzweig, O. Grzymkowska, K. Gudkova, C. Hadjivasiliou, O. Hartbrich, K. Hayasaka, H. Hayashii, M. Hernandez Villanueva, C. L. Hsu, A. Ishikawa, R. Itoh, M. Iwasaki, Y. Iwasaki, W. W. Jacobs, S. Jia, Y. Jin, C. W. Joo, K. K. Joo, K. H. Kang, G. Karyan, Y. Kato, H. Kichimi, C. H. Kim, D. Y. Kim, K. H. Kim, S. H. Kim, K. Kinoshita, P. Kodyš, T. Konno, A. Korobov, S. Korpar, E. Kovalenko, P. KriŽan, R. Kroeger, P. Krokovny, T. Kuhr, M. Kumar, R. Kumar, K. Kumara, A. Kuzmin, Y. J. Kwon, K. Lalwani, J. S. Lange, I. S. Lee, S. C. Lee, C. H. Li, L. K. Li, L. Li Gioi, J. Libby, K. Lieret, D. Liventsev, M. Masuda, D. Matvienko, J. T. McNeil, F. Metzner, R. Mizuk, G. B. Mohanty, T. J. Moon, T. Mori, R. Mussa, A. Natochii, L. Nayak, M. Nayak, M. Niiyama, N. K. Nisar, S. Nishida, K. Nishimura, S. Ogawa, H. Ono, Y. Onuki, P. Pakhlov, G. Pakhlova, T. Pang, S. Pardi, H. Park, S. Patra, S. Paul, T. K. Pedlar, R. Pestotnik, L. E. Piilonen, T. Podobnik, V. Popov, E. Prencipe, M. T. Prim, M. Röhrken, A. Rostomyan, N. Rout, G. Russo, D. Sahoo, Y. Sakai, S. Sandilya, L. Santelj, T. Sanuki, V. Savinov, G. Schnell, C. Schwanda, Y. Seino, K. Senyo, M. Shapkin, C. Sharma, J. G. Shiu, A. Sokolov, E. Solovieva, M. Starič, Z. S. Stottler, M. Sumihama, U. Tamponi, K. Tanida, F. Tenchini, M. Uchida, S. Uehara, T. Uglov, K. Uno, S. Uno, Y. Usov, R. Van Tonder, G. Varner, A. Vinokurova, A. Vossen, C. H. Wang, M. Z. Wang, P. Wang, X. L. Wang, M. Watanabe, S. Watanuki, E. Won, X. Xu, W. Yan, S. B. Yang, H. Ye, J. H. Yin, C. Z. Yuan, Z. P. Zhang, V. Zhilich, V. Zhukova

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Using data samples of 89.5 and 711 fb-1 recorded at energies of s=10.52 and 10.58 GeV, respectively, with the Belle detector at the KEKB e+e- collider, we report measurements of branching fractions of semileptonic decays Ξc0→Ξ-ℓ+νℓ (ℓ=e or μ) and the CP-asymmetry parameter of Ξc0→Ξ-π+ decay. The branching fractions are measured to be B(Ξc0→Ξ-e+νe)=(1.31±0.04±0.07±0.38)% and B(Ξc0→Ξ-μ+νμ)=(1.27±0.06±0.10±0.37)%, and the decay parameter αΞπ is measured to be 0.63±0.03±0.01 with much improved precision compared with the current world average. The corresponding ratio B(Ξc0→Ξ-e+νe)/B(Ξc0→Ξ-μ+νμ) is 1.03±0.05±0.07, which is consistent with the expectation of lepton flavor universality. The first measured asymmetry parameter ACP=(αΞ-π++αΞ¯+π-)/(αΞ-π+-αΞ¯+π-)=0.024±0.052±0.014 is found to be consistent with zero. The first and the second uncertainties above are statistical and systematic, respectively, while the third ones arise due to the uncertainty of the Ξc0→Ξ-π+ branching fraction.

Original languageEnglish
Article number121803
JournalPhysical review letters
Issue number12
Publication statusPublished - 2021 Sept 17

Bibliographical note

Funding Information:
Y. B. Li acknowledges the support from China Postdoctoral Science Foundation (2020TQ0079). 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 SINET5 network support. We acknowledge support from MEXT, JSPS, and Nagoya’s TLPRC (Japan); ARC (Australia); FWF (Austria); the National Natural Science Foundation of China under Contracts No. 11575017, No. 11761141009, No. 11975076, No. 12042509, and No. 12135005; the CAS Center for Excellence in Particle Physics (CCEPP); MSMT (Czechia); Carl Zeiss Foundation, DFG, Excellence Cluster Universe, and VolkswagenStiftung (Germany); DST (India); INFN (Italy); MOE, MSIP, NRF, Radiation Science Research Institute, Foreign Large-size Research Facility Application Supporting project, GSDC of KISTI and Korea Research Environment Open Network/Global Ring Network for Advanced Application Development (Korea); MNiSW and NCN (Poland); MSHE, Agreement 14.W03.31.0026 (Russia); University of Tabuk (Saudi Arabia); ARRS (Slovenia); IKERBASQUE (Spain); SNSF (Switzerland); MOE and MOST (Taiwan); and DOE and NSF (USA).

Publisher Copyright:
© 2021 authors. Published by the American Physical Society.

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)


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