Precision Measurement of the Baryon Lifetime

R Aaij, B Adeva, M Adinolfi, C Adrover, A Affolder… - Physical review …, 2013 - APS
R Aaij, B Adeva, M Adinolfi, C Adrover, A Affolder, Z Ajaltouni, J Albrecht, F Alessio
Physical review letters, 2013APS
The ratio of the Λ b 0 baryon lifetime to that of the B¯ 0 meson is measured using 1.0 fb-1 of
integrated luminosity in 7 TeV center-of-mass energy pp collisions at the LHC. The Λ b 0
baryon is observed for<? format?> the first time in the decay mode Λ b 0→ J/ψ p K-, while
the B¯ 0 meson decay used is the well known B¯ 0→ J/ψ π+ K-mode, where the π+ K-mass
is consistent with that of the K¯* 0 (892) meson. The ratio<? format?> of lifetimes is
measured to be 0.976±0.012±0.006, in agreement with theoretical expectations based< …
The ratio of the baryon lifetime to that of the meson is measured using of integrated luminosity in 7 TeV center-of-mass energy collisions at the LHC. The baryon is observed for <?format ?>the first time in the decay mode , while the meson decay used is the well known mode, where the mass is consistent with that of the meson. The ratio <?format ?>of lifetimes is measured to be , in agreement with theoretical expectations based <?format ?>on the heavy quark expansion. Using previous determinations of the meson lifetime, the lifetime is found to be . In both cases, the first uncertainty is statistical and the second systematic.
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