A search for B-s(0) oscillations is performed using a sample of semileptonic b-hadron decays collected by the ALEPH experiment during 1991-95. Compared to previous inclusive lepton analyses, the proper time resolution and b-flavour mistag rate are significantly improved. Additional sensitivity to B-s(0) mixing is obtained by identifying subsamples of events having a B-s(0) purity which is higher than the average for the whole data sample. Unbinned maximum likelihood amplitude fits are performed to derive a lower limit of Delta m(s) > 9.5 ps(-1) at the 95% confidence limit (95% CL). Combining with the ALEPH D-s(-)-based analyses yields Delta m(s) > 9.6 ps(-1) at 95% CL.
Search for B-s(0) oscillations using inclusive lepton events
ROLANDI, LUIGI;LIGABUE, FRANCO;LUSIANI, Alberto;
1999-01-01
Abstract
A search for B-s(0) oscillations is performed using a sample of semileptonic b-hadron decays collected by the ALEPH experiment during 1991-95. Compared to previous inclusive lepton analyses, the proper time resolution and b-flavour mistag rate are significantly improved. Additional sensitivity to B-s(0) mixing is obtained by identifying subsamples of events having a B-s(0) purity which is higher than the average for the whole data sample. Unbinned maximum likelihood amplitude fits are performed to derive a lower limit of Delta m(s) > 9.5 ps(-1) at the 95% confidence limit (95% CL). Combining with the ALEPH D-s(-)-based analyses yields Delta m(s) > 9.6 ps(-1) at 95% CL.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
