From a study of the kinematic properties of the final state produced in the semileptonic decays b --> Xlv(l), the inclusive charmless semileptonic branching ratio of b hadrons is measured. With a sample of 3.6 million hadronic Z decays recorded between 1992 and 1995 with the ALEPH detector at LEP, the value Br(b --> X(u)lv(l)) is determined to be (1.73 +/- 0.55(stat) +/- 0.55(syst)) x 10(-3), where X(u) represents any charmless hadronic state and b is a mixture of b hadrons weighted by their production rates. This measurement yields the result |V-ub|(2) = (18.68 +/- 5.94(stat) +/- 5.94(syst) +/- 1.45(HQE)) x 10(-6) where the last error comes from the conversion of the branching ratio to the CKM matrix element squared.
Determination of |V-ub| from the measurement of the inclusive charmless semileptonic branching ratio of b hadrons
G. Batignani;CIOCCI, MARIA AGNESE;FERRANTE, ISIDORO;FORTI, FRANCESCO;MESSINEO, ALBERTO MARIA;G. Rizzo;TONELLI, GUIDO EMILIO;
1999-01-01
Abstract
From a study of the kinematic properties of the final state produced in the semileptonic decays b --> Xlv(l), the inclusive charmless semileptonic branching ratio of b hadrons is measured. With a sample of 3.6 million hadronic Z decays recorded between 1992 and 1995 with the ALEPH detector at LEP, the value Br(b --> X(u)lv(l)) is determined to be (1.73 +/- 0.55(stat) +/- 0.55(syst)) x 10(-3), where X(u) represents any charmless hadronic state and b is a mixture of b hadrons weighted by their production rates. This measurement yields the result |V-ub|(2) = (18.68 +/- 5.94(stat) +/- 5.94(syst) +/- 1.45(HQE)) x 10(-6) where the last error comes from the conversion of the branching ratio to the CKM matrix element squared.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
