@article{e5643c918a194e9d93806b451e8435ab,
title = "First Observation of the B ¯ s0 → Λc+ Λ ¯ c- Decay and Evidence for the B ¯ 0 → Λc+ Λ ¯ c- Decay",
abstract = "A search is presented for the two-body charmed baryonic decays, B¯(s)0→Λc+Λ¯c-, using a data sample collected by the LHCb experiment during 2011-2012 and 2015-2018, corresponding to an integrated luminosity of 9 fb-1. The first observation of the B¯s0→Λc+Λ¯c- decay is reported with 6.2σ significance along with 4.3σ evidence for the B¯0→Λc+Λ¯c- decay. The branching fractions are measured to be B(B¯0→Λc+Λ¯c-)=(1.01-0.28+0.27±0.08±0.15)×10-5 and B(B¯s0→Λc+Λ¯c-)=(5.0±1.3±0.5±0.8)×10-5, where the first uncertainty is statistical, the second systematic, and the third due to external inputs. These results provide novel experimental inputs for the theoretical framework describing two-body baryonic decays of B mesons via W-emission and W-exchange mechanisms.",
keywords = "Physics",
author = "\{LHCb Collaboration\} and R. Aaij and Abdelmotteleb, \{A. S.W.\} and \{Abellan Beteta\}, C. and F. Abudin{\'e}n and T. Ackernley and Adefisoye, \{A. A.\} and B. Adeva and M. Adinolfi and P. Adlarson and C. Agapopoulou and Aidala, \{C. A.\} and Z. Ajaltouni and S. Akar and K. Akiba and M. Akthar and P. Albicocco and J. Albrecht and R. Aleksiejunas and F. Alessio and \{Alvarez Cartelle\}, P. and R. Amalric and S. Amato and Amey, \{J. L.\} and Y. Amhis and L. An and L. Anderlini and M. Andersson and P. Andreola and M. Andreotti and \{Andres Estrada\}, S. and A. Anelli and D. Ao and C. Arata and F. Archilli and Z. Areg and M. Argenton and \{Arguedas Cuendis\}, S. and L. Arnone and A. Artamonov and M. Artuso and E. Aslanides and \{Ata{\'i}de Da Silva\}, R. and M. Atzeni and B. Audurier and Authier, \{J. A.\} and D. Bacher and \{Bachiller Perea\}, I. and E. Golobardes and \{Valls Canudas\}, N. and X. Vilasis-Cardona and \{Calvo G{\'o}mez\}, M{\'i}riam",
note = "Publisher Copyright: {\textcopyright} 2026 CERN, for the LHCb Collaboration. Published by the American Physical Society under the terms of the {"}https://creativecommons.org/licenses/by/4.0/{"}Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP",
year = "2026",
month = feb,
day = "13",
doi = "10.1103/cxn3-8t4g",
language = "English",
volume = "136",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "6",
}