Search for the ${\Lambda }_b\to \Lambda {\eta }^{\prime }$ and ${\Lambda }_b\to \Lambda \eta$ decays with the LHCb detector

Abstract

A search is performed for the as yet unobserved baryonic ${\Lambda }_b\to \Lambda {\eta }^{\prime }$ and ${\Lambda }_b\to \Lambda \eta$ decays with 3$f{b}^{-1}$ of proton-proton collision data recorded by the LHCb experiment. The $B^0\to K_S^0{\eta }^{\prime }$ decay is used as a normalisation channel. No significant signal is observed for the ${\Lambda }_b\to \Lambda {\eta }^{\prime }$ decay. An upper limit is found on the branching fraction of $\mathcal{B}({\Lambda }_b\to \Lambda {\eta }^{\prime })<3.1\times 10^{-6}$} at 90\% confidence level. Evidence is seen for the presence of the ${\Lambda }_b\to \Lambda \eta$ decay at the level of $3\sigma$ significance, with a branching fraction $\mathcal{B}({\Lambda }_b\to \Lambda \eta )=(9.3_{-5.3}^{+7.3})\times 10^{-6}$}.

22 pages, 6 figures. v2 is published version (very minor revisions)

References in corpus (5)

• Big-Bang Nucleosynthesis
• Boosted Decision Trees as an Alternative to Artificial Neural Networks for Particle Identification
• Performance of the LHCb Vertex Locator
• A global fit to determine the pseudoscalar mixing angle and the gluonium content of the eta' meson
• Decays of $J/\psi$ and ${\psi }^{\prime }$ into vector and pseudoscalar meson and the pseudoscalar glueball-$q\bar{q}$ mixing

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