The lifetime of the Bs(0) meson is measured in approximately 3 million hadronic Z decays accumulated using the ALEPH detector at LEP from 1991 to 1994. Seven different Ds(-) decay modes were reconstructed and combined with an opposite sign lepton as evidence of semileptonic Bs(0) decays. Two hundred and eight D(s)(-)l(+) candidates satisfy selection criteria designed to ensure precise proper time reconstruction and yield a measured Bs(0) lifetime of tau(Bs(0)) = 1.59(-0.15)(+0.17) (stat) +/-0.03 (syst) ps. Using a larger, less constrained sample of events, the product branching ratio is measured to be Br((b) over bar -> Bs(0))xBr(Bs(0) -> D(s)(-)l(+)nu X) = 0.82 +/- 0.09 (stat)(-0.14)(+0.13) (syst) %.
Measurement of the Bs(0) Lifetime and Production rate With D-s(-)l(+) Combinations In Z decays
BATIGNANI, GIOVANNI;BETTARINI, STEFANO;CIOCCI, MARIA AGNESE;FERRANTE, ISIDORO;FORTI, FRANCESCO;GIORGI, MARCELLO;MESSINEO, ALBERTO MARIA;RIZZO, GIULIANA;TONELLI, GUIDO EMILIO;G. TRIGGIANI;
1995-01-01
Abstract
The lifetime of the Bs(0) meson is measured in approximately 3 million hadronic Z decays accumulated using the ALEPH detector at LEP from 1991 to 1994. Seven different Ds(-) decay modes were reconstructed and combined with an opposite sign lepton as evidence of semileptonic Bs(0) decays. Two hundred and eight D(s)(-)l(+) candidates satisfy selection criteria designed to ensure precise proper time reconstruction and yield a measured Bs(0) lifetime of tau(Bs(0)) = 1.59(-0.15)(+0.17) (stat) +/-0.03 (syst) ps. Using a larger, less constrained sample of events, the product branching ratio is measured to be Br((b) over bar -> Bs(0))xBr(Bs(0) -> D(s)(-)l(+)nu X) = 0.82 +/- 0.09 (stat)(-0.14)(+0.13) (syst) %.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.