The lifetimes of the (B)over-bar-0 and B- mesons have been measured with the ALEPH detector at LEP. Semileptonic decays of (B)over-bar-0 and B- mesons were partially reconstructed by identifying events containing a lepton with an associated D*+ or D0 meson. The proper time of the B meson was estimated from the measured decay length and the momentum and mass of the D-lepton system. A fit to the proper time of 77 D*+ l- and 77 D0 l- candidates, combined with a constraint on the lifetime ratio (tau-/tau0) arising from the relative rates of observed D*+l- and D0l- events, yielded the following lifetimes: tau0 = 1.52(+0.20/-0.18)(stat.)+0.00/-0.13 (syst.) ps, tau = 1.47 +(+0.22/-0.19) (stat.) + (0.15/-0.14) (syst.) ps, tau-/tau0 = 0.96 + (+0.19/-0.15) (stat. ) + (+0.18/-0.12)(syst.).
Measurement of the (B)over-bar-0 and B- meson Lifetimes
G. BATIGNANI;CIOCCI, MARIA AGNESE;FERRANTE, ISIDORO;FIDECARO, FRANCESCO;FORTI, FRANCESCO;GIORGI, MARCELLO;MESSINEO, ALBERTO MARIA;RIZZO, GIULIANA;TONELLI, GUIDO EMILIO;G. TRIGGIANI;
1993-01-01
Abstract
The lifetimes of the (B)over-bar-0 and B- mesons have been measured with the ALEPH detector at LEP. Semileptonic decays of (B)over-bar-0 and B- mesons were partially reconstructed by identifying events containing a lepton with an associated D*+ or D0 meson. The proper time of the B meson was estimated from the measured decay length and the momentum and mass of the D-lepton system. A fit to the proper time of 77 D*+ l- and 77 D0 l- candidates, combined with a constraint on the lifetime ratio (tau-/tau0) arising from the relative rates of observed D*+l- and D0l- events, yielded the following lifetimes: tau0 = 1.52(+0.20/-0.18)(stat.)+0.00/-0.13 (syst.) ps, tau = 1.47 +(+0.22/-0.19) (stat.) + (0.15/-0.14) (syst.) ps, tau-/tau0 = 0.96 + (+0.19/-0.15) (stat. ) + (+0.18/-0.12)(syst.).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.