Spadaro Norella, E. (2019) First observation of B0 (s) → J/ψ pp decays and precise measurement of B0 (s) masses. Il nuovo cimento C, 42 (5). pp. 1-10. ISSN 1826-9885
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Abstract
In this article the first observation of B0 (s) → J/ψ pp is reported along with the most precise B0 (s) mass measurements. The analysis is performed using the data sample collected by LHCb during 2011–2016, corresponding to an integrated luminosity of 5.2 fb−1. The B0 (s) → J/ψ pp decays are suppressed due to the OZI and Cabibbo rules, as well as due to the limited available phase space. The branching fractions are measured to be B(B0 → J/ψ pp) = (4.51±0.40 (stat) ± 0.44 (syst)) ×10−7 and B(B0 s → J/ψ pp) = (3.58±0.19 (stat) ± 0.39 (syst)) ×10−6. The B0 s branching fraction is two order of magnitude higher than a na¨ıve expectation of O(10−9). The suppression can be lifted by the existence of pentaquarks and glueballs in the J/ψ p and pp system, respectively. In addition, due to the limited available phase space, the most precise mass measurements are permitted. The measured value of the B0 mass is 5279.74 ± 0.30 (stat) ± 0.10 (syst) MeV, and that of the B0 s mass is 5366.85 ± 0.19 (stat) ± 0.13 (syst) MeV.
Item Type: | Article |
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Subjects: | 500 Scienze naturali e Matematica > 530 Fisica |
Depositing User: | Marina Spanti |
Date Deposited: | 21 Dec 2020 13:45 |
Last Modified: | 21 Dec 2020 13:45 |
URI: | http://eprints.bice.rm.cnr.it/id/eprint/20634 |
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