2025/07/16 by LHCb collaboration, R. Aaij, Aaij, R. +2354 · 1 voice
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #hep-ex
paper · pdf · doi:10.48550/arxiv.2507.12402
arxiv published 2025/07/16 · arxiv updated 2025/09/30
A sample of pp collision data, corresponding to an integrated luminosity of 5.4 fb-1 and collected by the LHCb experiment during LHC Run 2, is used to measure the ratio of the lifetime of the \itΞb0 baryon to that of the \itΛb0 baryon, rτ≡τ_\itΞb0/τ_\itΛb0. The value rτ\rm Run 2=1.004±0.009±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 = 1.004±0.008±0.005. Multiplying by the known value of the \itΛb0 lifetime yields τ_\itΞb0 = 1.475±0.012±0.008±0.009~\rm ps, where the last uncertainty is due to the limited knowledge of the \itΛb0 lifetime. This measurement improves the precision of the current world average of the \itΞb0 lifetime by about a factor of two, and is in good agreement with the most recent theoretical predictions.