Using proton-proton collision data, collected with the LHCb detector and corresponding to 1.0, 2.0 and 1.9 fb−1 of integrated luminosity at the centre-of-mass energies of 7, 8, and 13 TeV, respectively, the decay Λb0→χc1(3872)pK− with χc1(3872) → J/ψ π+π− is observed for the first time. The significance of the observed signal is in excess of seven standard deviations. It is found that (58 ± 15)% of the decays proceed via the two-body intermediate state χc1(3872)Λ(1520). The branching fraction with respect to that of the Λb0 → ψ(2S)pK− decay mode, where the ψ(2S) meson is reconstructed in the J/ψ π+π− final state, is measured to be:β(Λb0→χc1(3872)pK−)β(Λb0→ψ(2S)pK−)×β(χc1(3872)→J/ψπ+π−)β(ψ(2S)→J/ψπ+π−)=(5.4±1.1±0.2)×10−2, where the first uncertainty is statistical and the second is systematic. [Figure not available: see fulltext.]
Observation of the Λb0→χc1 (3872) pK− decay
Calabrese R.;Capriotti L.;Fiorini M.;Luppi E.;Minzoni L.;Pappalardo L. L.;Skiba I.;Tomassetti L.;
2019
Abstract
Using proton-proton collision data, collected with the LHCb detector and corresponding to 1.0, 2.0 and 1.9 fb−1 of integrated luminosity at the centre-of-mass energies of 7, 8, and 13 TeV, respectively, the decay Λb0→χc1(3872)pK− with χc1(3872) → J/ψ π+π− is observed for the first time. The significance of the observed signal is in excess of seven standard deviations. It is found that (58 ± 15)% of the decays proceed via the two-body intermediate state χc1(3872)Λ(1520). The branching fraction with respect to that of the Λb0 → ψ(2S)pK− decay mode, where the ψ(2S) meson is reconstructed in the J/ψ π+π− final state, is measured to be:β(Λb0→χc1(3872)pK−)β(Λb0→ψ(2S)pK−)×β(χc1(3872)→J/ψπ+π−)β(ψ(2S)→J/ψπ+π−)=(5.4±1.1±0.2)×10−2, where the first uncertainty is statistical and the second is systematic. [Figure not available: see fulltext.]File | Dimensione | Formato | |
---|---|---|---|
Aaij2019_Article_ObservationOfTheÎb0Χc1LambdaMa.pdf
accesso aperto
Descrizione: Full text editoriale
Tipologia:
Full text (versione editoriale)
Licenza:
Creative commons
Dimensione
510.44 kB
Formato
Adobe PDF
|
510.44 kB | Adobe PDF | Visualizza/Apri |
I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.