First observation of the decay Λ<i><sub>b</sub></i><SUP>0</SUP> → η<i><sub>c</sub></i> (1<i>S</i>)<i>pK</i><SUP>-</SUP>



Aaij, R, Beteta, C Abellan, Ackernley, T, Adeva, B, Adinolfi, M, Afsharnia, H, Aidala, CA, Aiola, S, Ajaltouni, Z, Akar, S
et al (show 985 more authors) (2020) First observation of the decay Λ<i><sub>b</sub></i><SUP>0</SUP> → η<i><sub>c</sub></i> (1<i>S</i>)<i>pK</i><SUP>-</SUP>. PHYSICAL REVIEW D, 102 (11). 112012-.

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Abstract

The decay $\Lambda_b^0 \to \eta_c(1S) p K^-$ is observed for the first time using a data sample of proton-proton collisions, corresponding to an integrated luminosity of 5.5 $fb^{-1}$, collected with the LHCb experiment at a center-of-mass energy of 13 TeV. The branching fraction of the decay is measured, using the $\Lambda_b^0 \to J/\psi p K^-$ decay as a normalization mode, to be $\mathcal{B}(\Lambda_b^0 \to \eta_c(1S) p K^-)=(1.06\pm0.16\pm0.06^{+0.22}_{-0.19})\times10^{-4}$, where the quoted uncertainties are statistical, systematic and due to external inputs, respectively. A study of the $\eta_c(1S) p$ mass spectrum is performed to search for the $P_c(4312)^+$ pentaquark state. No evidence is observed and an upper limit of \begin{equation*} \frac{\mathcal{B}(\Lambda_b^0 \to P_c(4312)^+ K^-)\times \mathcal{B}(P_c(4312)^+ \to \eta_c(1S) p)}{\mathcal{B}(\Lambda_b^0 \to \eta_c(1S) p K^-)} < 0.24 \end{equation*} is obtained at the 95% confidence level.

Item Type: Article
Additional Information: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2020-012.html (LHCb public pages)
Uncontrolled Keywords: hep-ex, hep-ex
Depositing User: Symplectic Admin
Date Deposited: 27 Jan 2021 09:12
Last Modified: 18 Oct 2023 08:36
DOI: 10.1103/PhysRevD.102.112012
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3114855