Precision measurement of the ${\Xi }_b^{-}$ baryon lifetime

Abstract

A sample of $pp$ collision data, corresponding to an integrated luminosity of 5.5 fb${}^{-1}$ and collected by the LHCb experiment during LHC Run 2, is used to measure the ratio of the lifetime of the ${\Xi }_b^{-}$ baryon to that of the ${\Lambda }_b^0$ baryon, $r_{\tau }\equiv {\tau }_{{\Xi }_b^{-}}/{\tau }_{{\Lambda }_b^0}$. The value $r_{\tau }=1.076\pm 0.013\pm 0.006$ is obtained, where the first uncertainty is statistical and the second systematic. This value is averaged with the corresponding value from Run 1 to obtain $r_{\tau }^{\mathrm{Run}1,2}=1.078\pm 0.012\pm 0.007$. Multiplying by the world-average value of the ${\Lambda }_b^0$ lifetime yields ${\tau }_{{\Xi }_b^{-}}^{\mathrm{Run}1,2}=1.578\pm 0.018\pm 0.010\pm 0.011$ ps, where the uncertainties are statistical, systematic, and due to the limited knowledge of the ${\Lambda }_b^0$ lifetime. This measurement improves the precision of the current world average of the ${\Xi }_b^{-}$ lifetime by about a factor of two, and is in good agreement with the most recent theoretical predictions.

arXiv comment12 pages, 5 figures. All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2014-010.html (LHCb public pages)

References in corpus (24)

• PYTHIA 6.4 Physics and Manual
• PYTHIA 6.2 Physics and Manual
• A Brief Introduction to PYTHIA 8.1
• LHCb Detector Performance
• sPlot: a statistical tool to unfold data distributions
• Performance of the LHCb RICH detector at the LHC
• Performance of the LHCb Vertex Locator
• Efficient, reliable and fast high-level triggering using a bonsai boosted decision tree
• Performance of the LHCb muon system
• Selection and processing of calibration samples to measure the particle identification performance of the LHCb experiment in Run 2
• Improved performance of the LHCb Outer Tracker in LHC Run 2
• Design and performance of the LHCb trigger and full real-time reconstruction in Run 2 of the LHC
• Direct observation of the strange b baryon Xi_b^{-}
• B Decays and CP Violation
• Observation and Mass Measurement of the Baryon ${\Xi }_b^{-}$
• LHCb Topological Trigger Reoptimization
• ReDecay: A novel approach to speed up the simulation at LHCb
• Precision measurement of the mass and lifetime of the Xi_b^- baryon
• Kernel density estimation of a multidimensional efficiency profile
• Mass and lifetime measurements of bottom and charm baryons in $p\bar{p}$ collisions at $\sqrt{s}= 1.96 TeV
• Precision measurement of the ${\Lambda }_c^{+}$, ${\Xi }_c^{+}$ and ${\Xi }_c^0$ baryon lifetimes
• Measurement of the ${\Xi }_b^{-}$ and ${\Omega }_b^{-}$ baryon lifetimes
• Quark-hadron duality at work: lifetimes of bottom baryons
• Observation and branching fraction measurement of the decay ${\Xi }_b^{-}\to {\Lambda }_b^0{\pi }^{-}$

Cited by in corpus (1)

• Precision measurement of the ${\Xi }_b^0$ baryon lifetime