TY  - JOUR
AU  - LHCb Collaboration (Aaij, R. et al
AU  - Martinez-Vidal, F.
AU  - Oyanguren, A.
AU  - Ruiz Valls, P.
AU  - Sanchez Mayordomo, C.
PY  - 2014
DA  - 2014//
TI  - Precision Measurement of the Mass and Lifetime of the Xi(0)(b) Baryon
T2  - Phys. Rev. Lett.
JO  - Physical Review Letters
SP  - 032001
EP  - 10pp
VL  - 113
IS  - 3
PB  - Amer Physical Soc
AB  - Using a proton-proton collision data sample corresponding to an integrated luminosity of 3 fb(-1) collected by LHCb at center-of-mass energies of 7 and 8 TeV, about 3800 Xi(0)(b) -> Xi(+)(c)pi(-), Xi(+)(c) -> pK(-)pi(+) signal decays are reconstructed. From this sample, the first measurement of the Xi(0)(b) baryon lifetime is made, relative to that of the Lambda(0)(b) baryon. The mass differences M(Xi(0)(b)) – M(Lambda(0)(b)) and M(Xi(+)(c)) – M(Lambda(+)(c)) are also measured with precision more than 4 times better than the current world averages. The resulting values are tau(Xi b0)/tau(Lambda b0) = 1.006 +/- 0.018 +/- 0.010, M(Xi(0)(b)) – M(Lambda(0)(b)) = 172.44 +/- 0.39 +/- 0.17 MeV/c(2), M(Xi(+)(c)) – M(Lambda(+)(c)) = 181.51 +/- 0.14 +/- 0.10 MeV/c(2), where the first uncertainty is statistical and the second is systematic. The relative rate of Xi(0)(b) to Lambda(0)(b) baryon production is measured to be f(Xi b0) B(Xi(0)(b) -> Xi(+)(c)pi(-)) B(Xi(+)(c) -> pK(-)pi(+))/f(Lambda b0) B(Lambda(0)(b) -> Lambda(+)(c)pi(-)) B(Lambda(+)(c) -> pK(-)pi(+)) = (1.88 +/- 0.04 +/- 0.03) x 10(-2), where the first factor is the ratio of fragmentation fractions, b -> Xi(0)(b) relative to b -> Lambda(0)(b). Relative production rates as functions of transverse momentum and pseudorapidity are also presented.
SN  - 0031-9007
UR  - http://arxiv.org/abs/1405.7223
UR  - https://doi.org/10.1103/PhysRevLett.113.032001
DO  - 10.1103/PhysRevLett.113.032001
LA  - English
N1  - WOS:000341260100003
ID  - LHCbCollaborationAaij_etal2014
ER  -