Observation of Λ<sub>b</sub><SUP>0</SUP> → ψ (2S)pK<SUP>-</SUP> and Λ<sub>b</sub><SUP>0</SUP> → J/ψπ<SUP>+</SUP>π<SUP>-</SUP>pK<SUP>-</SUP> decays and a measurement of the A<sub>b</sub><SUP>0</SUP> baryon mass



Aaij, R, Beteta, C Abellan, Adeva, B, Adinolfi, M, Affolder, A, Ajaltouni, Z, Akar, S, Albrecht, J, Alessio, F, Alexander, M
et al (show 726 more authors) (2016) Observation of Λ<sub>b</sub><SUP>0</SUP> → ψ (2S)pK<SUP>-</SUP> and Λ<sub>b</sub><SUP>0</SUP> → J/ψπ<SUP>+</SUP>π<SUP>-</SUP>pK<SUP>-</SUP> decays and a measurement of the A<sub>b</sub><SUP>0</SUP> baryon mass. JOURNAL OF HIGH ENERGY PHYSICS, 1605 (5). 132-.

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Abstract

The decays $ \Lambda_b^0 \to \psi(2S)pK^-$ and $ \Lambda_b^0 \to J/\psi \pi^+ \pi^- pK^-$ are observed in a data sample corresponding to an integrated luminosity of 3fb$^{-1}$, collected in proton-proton collisions at 7 and 8TeV centre-of-mass energies by the LHCb detector. The $\psi(2S)$ mesons are reconstructed through the decay modes $\psi(2S)\to\mu^+\mu^-$ and $\psi(2S)\to J/\psi\pi^+\pi^-$. The branching fractions relative to that of $ \Lambda_b^0 \to J/\psi pK^-$ are measured to be \begin{eqnarray*} \frac{\mathcal{B}(\Lambda_b^0 \to \psi(2S) pK^-)} {\mathcal{B}(\Lambda_b^0 \to J/\psi pK^-)} & = & (20.70\pm 0.76\pm 0.46\pm 0.37)\times10^{-2} \,, \frac{\mathcal{B}(\Lambda_b^0 \to J/\psi \pi^+ \pi^- pK^-)} {\mathcal{B}(\Lambda_b^0 \to J/\psi pK^-)} & = & (20.86\pm 0.96\pm 1.34)\times10^{-2} \,, \end{eqnarray*} where the first uncertainties are statistical, the second are systematic and the third is related to the knowledge of $J/\psi$ and $\psi(2S)$ branching fractions. The mass of the $\Lambda_b^0$ baryon is measured to be $$ M(\Lambda_b^0) = 5619.65 \pm 0.17 \pm 0.17\mathrm{MeV}/c^2,$$ where the uncertainties are statistical and systematic.

Item Type: Article
Additional Information: 21 pages, 6 figures. All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-060.html
Uncontrolled Keywords: B physics, Flavor physics, Hadron-Hadron scattering (experiments), Particle and resonance production, Spectroscopy
Depositing User: Symplectic Admin
Date Deposited: 07 Jun 2016 11:18
Last Modified: 18 Oct 2023 01:14
DOI: 10.1007/JHEP05(2016)132
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3001573