The ratio of the Lambda(0)(b) baryon lifetime to that of the (B) over bar (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 Lambda(0)(b) baryon is observed for the first time in the decay mode Lambda(0)(b) -> J/psi pK(-), while the (B) over bar (0) meson decay used is the well known (B) over bar (0) J/psi pi K-+(-) mode, where the pi K-+(-) mass is consistent with that of the (K) over bar*(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) over bar (0) meson lifetime, the Lambda(0)(b) lifetime is found to be 1.482 +/- 0.018 +/- 0.012 ps. In both cases, the first uncertainty is statistical and the second systematic.
Archilli, F., Carboni, G., Santovetti, E., The LHCb, C. (2013). Precision Measurement of the Lambda(0)(b) Baryon Lifetime. PHYSICAL REVIEW LETTERS, 111(10) [10.1103/PhysRevLett.111.102003].
Precision Measurement of the Lambda(0)(b) Baryon Lifetime
Archilli, FMembro del Collaboration Group
;Carboni, GMembro del Collaboration Group
;Santovetti, EMembro del Collaboration Group
;
2013-01-01
Abstract
The ratio of the Lambda(0)(b) baryon lifetime to that of the (B) over bar (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 Lambda(0)(b) baryon is observed for the first time in the decay mode Lambda(0)(b) -> J/psi pK(-), while the (B) over bar (0) meson decay used is the well known (B) over bar (0) J/psi pi K-+(-) mode, where the pi K-+(-) mass is consistent with that of the (K) over bar*(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) over bar (0) meson lifetime, the Lambda(0)(b) 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 IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.