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キーワード:
B Physics, Hadron-Hadron Scattering, QCD, Spectroscopy
MPINP:
LHCb - Abteilung Hinton
要旨:
The first observation of the Bc+ → J/ψπ+π0 decay is reported with high significance using proton-proton collision data, corresponding to an integrated luminosity of 9 fb−1, collected with the LHCb detector at centre-of-mass energies of 7, 8, and 13 TeV. The ratio of its branching fraction relative to the Bc+ → J/ψπ+ channel is measured to be
BBc+ →J/ψπ+π0 / BBc+ →J/ψπ+ = 2.80 ± 0.15 ± 0.11 ± 0.16 ,
where the first uncertainty is statistical, the second systematic and the third related to imprecise knowledge of the branching fractions for B+ → J/ψK∗+ and Bc+ → J/ψπ+ decays, which are used to determine the π0 detection efficiency. The π+π0 mass spectrum is found to be consistent with the dominance of an intermediate ρ+ contribution in accordance with a model based on QCD factorisation.