Measurement of the mass difference and relative production rate of the Ωb- and Ξb- baryons

R. Aaij*, A. S.W. Abdelmotteleb, C. Abellan Beteta, F. Abudinén, T. Ackernley, B. Adeva, M. Adinolfi, P. Adlarson, H. Afsharnia, C. Agapopoulou, C. A. Aidala, Z. Ajaltouni, S. Akar, K. Akiba, P. Albicocco, J. Albrecht, F. Alessio, M. Alexander, A. Alfonso Albero, Z. AlioucheP. Alvarez Cartelle, R. Amalric, S. Amato, J. L. Amey, Y. Amhis, L. An, L. Anderlini, M. Andersson, A. Andreianov, M. Andreotti, D. Andreou, D. Ao, F. Archilli, A. Artamonov, M. Artuso, E. Aslanides, M. Atzeni, B. Audurier, I. B.Bachiller Perea, S. Bachmann, M. Bachmayer, J. J. Back, A. Bailly-Reyre, P. Baladron Rodriguez, V. Balagura, W. Baldini, J. Baptista De Souza Leite, M. Barbetti, R. J. Barlow, S. Barsuk, LHCb collaboration, Carolina da silva Bolognani, Daniel Hugo Cámpora Pérez, Jacco de Vries, Miriam Lucio Martinez, Marcel Merk, Davide Nicotra, Chris Pawley, Keri Vos

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

The mass difference between the Ω−b and Ξ−b baryons is measured using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9  fb−1, and is found to be m(Ω−b)−m(Ξ−b)=248.54±0.51(stat)±0.38(syst)  MeV/c2. The mass of the Ω−b baryon is measured to be m(Ω−b)=6045.9±0.5(stat)±0.6(syst)  MeV/c2. This is the most precise determination of the Ω−b mass to date. In addition, the production rate of Ω−b baryons relative to that of Ξ−b baryons is measured for the first time in pp collisions, using an LHCb dataset collected at a center-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 6  fb−1. Reconstructing beauty baryons in the kinematic region 2<η<6 and pT<20  GeV/c with their decays to a J/ψ meson and a hyperon, the ratio fΩ−bfΞ−b×B(Ω−b→J/ψΩ−)B(Ξ−b→J/ψΞ−)=0.120±0.008(stat)±0.008(syst), is obtained, where fΩ−b and fΞ−b are the fragmentation fractions of b quarks into Ω−b and Ξ−b baryons, respectively, and B represents the branching fractions of their respective decays.
Original languageEnglish
Article number052008
Number of pages16
JournalPhysical Review D
Volume108
Issue number5
DOIs
Publication statusPublished - 18 Sept 2023

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