The ratio of the Λb0 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 Λb0 baryon is observed for the first time in the decay mode Λb0→J/ψpK-, while the B¯0 meson decay used is the well known B¯0→J/ψπ+K- mode, where the π+K- mass is consistent with that of the K¯*0(892) meson. The ratio of lifetimes is measured to be 0.976±0.012±0.006, in agreement with theoretical expectations based on the heavy quark expansion. Using previous determinations of the B¯0 meson lifetime, the Λb0 lifetime is found to be 1.482±0.018±0.012 ps. In both cases, the first uncertainty is statistical and the second systematic.
Precision Measurement of the Λ_{b}^{0} Baryon Lifetime
BALDINI, Wander;BOZZI, Concezio;FIORE, Marco;SAVRIE', Mauro;
2013
Abstract
The ratio of the Λb0 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 Λb0 baryon is observed for the first time in the decay mode Λb0→J/ψpK-, while the B¯0 meson decay used is the well known B¯0→J/ψπ+K- mode, where the π+K- mass is consistent with that of the K¯*0(892) meson. The ratio of lifetimes is measured to be 0.976±0.012±0.006, in agreement with theoretical expectations based on the heavy quark expansion. Using previous determinations of the B¯0 meson lifetime, the Λb0 lifetime is found to be 1.482±0.018±0.012 ps. In both cases, the first uncertainty is statistical and the second systematic.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.