2024/06/17 by LHCb collaboration, R. Aaij, A. S. W. Abdelmotteleb +1067 · 1 voice
Physics and Astronomy · #hep-ex
paper · pdf · doi:10.1103/physrevd.110.072002
arxiv published 2024/06/17 · arxiv updated 2024/10/04
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 Ξ-b baryon to that of the Λ0b baryon, rτ≡τΞ-b/τΛ0b. The value rτ=1.076±0.013±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 rτ\rm Run 1,2 = 1.078±0.012±0.007. Multiplying by the world-average value of the Λ0b lifetime yields τΞ-b\rm Run~1,2 = 1.578±0.018±0.010±0.011 ps, where the uncertainties are statistical, systematic, and due to the limited knowledge of the Λ0b lifetime. This measurement improves the precision of the current world average of the Ξ-b lifetime by about a factor of two, and is in good agreement with the most recent theoretical predictions.