Study of the production of ${\Lambda }_b^0$ and ${\overline{B}}^0$ hadrons in $pp$ collisions and first measurement of the ${\Lambda }_b^0\to J/\psi p{K}^{-}$ branching fraction

Abstract

The product of the ${\Lambda }_b^0$ (${\overline{B}}^0$) differential production cross-section and the branching fraction of the decay ${\Lambda }_b^0\to J/\psi p{K}^{-}$ (${\overline{B}}^0\to J/\psi {\overline{K}}^{\ast }(892{)}^0$) is measured as a function of the beauty hadron transverse momentum, $p_{\mathrm{T}}$, and rapidity, $y$. The kinematic region of the measurements is $p_{\mathrm{T}}<20\mathrm{GeV}/c$ and $2.0<y<4.5$. The measurements use a data sample corresponding to an integrated luminosity of $3{\mathrm{fb}}^{-1}$ collected by the LHCb detector in $pp$ collisions at centre-of-mass energies $\sqrt{s}=7\mathrm{TeV}$ in 2011 and $\sqrt{s}=8\mathrm{TeV}$ in 2012. Based on previous LHCb results of the fragmentation fraction ratio, $f_{{\Lambda }_B^0}/f_d$, the branching fraction of the decay ${\Lambda }_b^0\to J/\psi p{K}^{-}$ is measured to be \begin{equation*} \mathcal{B}(Λ_b^0\rightarrow J/ψpK^-)= (3.17\pm0.04\pm0.07\pm0.34^{+0.45}_{-0.28})\times10^{-4}, \end{equation*} where the first uncertainty is statistical, the second is systematic, the third is due to the uncertainty on the branching fraction of the decay ${\overline{B}}^0\to J/\psi {\overline{K}}^{\ast }(892{)}^0$, and the fourth is due to the knowledge of $f_{{\Lambda }_b^0}/f_d$. The sum of the asymmetries in the production and decay between ${\Lambda }_b^0$ and ${\overline{\Lambda }}_b^0$ is also measured as a function of $p_{\mathrm{T}}$ and $y$. The previously published branching fraction of ${\Lambda }_b^0\to J/\psi p{\pi }^{-}$, relative to that of ${\Lambda }_b^0\to J/\psi p{K}^{-}$, is updated. The branching fractions of ${\Lambda }_b^0\to P_c^{+}(\to J/\psi p)K^{-}$ are determined.

29 pages, 19figures. 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-2015-032.html

References in corpus (9)

• PYTHIA 6.4 Physics and Manual
• Observation of $J/\psi p$ resonances consistent with pentaquark states in ${\Lambda }_b^0\to J/\psi K^{-}p$ decays
• Boosted Decision Trees as an Alternative to Artificial Neural Networks for Particle Identification
• Performance of the LHCb Vertex Locator
• Measurement of $CP$ asymmetry in $D^0\to K^{-}{K}^{+}$ and $D^0\to {\pi }^{-}{\pi }^{+}$ decays
• Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV
• Λ_{c} enhancement from strongly coupled quark-gluon plasma
• Observation of the ${\Lambda }_b^0\to J/\psi p{\pi }^{-}$ decay
• Asymmetry in ${\Lambda }_b$ and ${\bar{\Lambda }}_b$ production

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