Study of the ${\mathrm{B}}^{+}\to \mathrm{J}/\uppsi \overline{\Lambda}\mathrm{p}$ decay in proton-proton collisions at $\sqrt{s}$ = 8 TeV

Abstract

A study of the ${\mathrm{B}}^{+}\to \mathrm{J}/\uppsi \overline{\Lambda}\mathrm{p}$ decay using proton-proton collision data collected at $\sqrt{s}$ = 8 TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 19.6 fb⁻¹, is presented. The ratio of branching fractions $\mathcal{B}\left({\mathrm{B}}^{+}\to \mathrm{J}/\uppsi \overline{\Lambda}\mathrm{p}\right)/\mathcal{B}\left({\mathrm{B}}^{+}\to \mathrm{J}/{\uppsi \mathrm{K}}^{\ast }{(892)}^{+}\right)$ is measured to be (1.054 ± 0.057(stat) ± 0.035(syst) ± 0.011($\mathcal{B}$))%, where the last uncertainty reflects the uncertainties in the world-average branching fractions of $\overline{\Lambda}$ and K^*(892) ⁺ decays to reconstructed final states. The invariant mass distributions of the $\mathrm{J}/\uppsi \overline{\Lambda}$, J/ψp, and $\overline{\Lambda}\mathrm{p}$ systems produced in the ${\mathrm{B}}^{+}\to \mathrm{J}/\uppsi \overline{\varLambda}\mathrm{p}$ decay are investigated and found to be inconsistent with the pure phase space hypothesis. The analysis is extended by using a model-independent angular amplitude analysis, which shows that the observed invariant mass distributions are consistent with the contributions from excited kaons decaying to the $\overline{\Lambda}\mathrm{p}$ system.

A preprint version of the article is available at ArXiv.