Study of B0s oscillations and lifetime using fully reconstructed D̄s decays

• Main Authors: BARATE, R., THULASIDAS, M.
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 1998
• Subjects: Computer Sciences; Databases and Information Systems
• Online Access: https://ink.library.smu.edu.sg/sis_research/5864; https://ink.library.smu.edu.sg/context/sis_research/article/6867/viewcontent/Study_of_B0_s_oscillations_and_lifetime_using_full.pdf
• Institution: Singapore Management University

A search for B0sBs0 oscillations is performed using approximately 4 million Z→qq¯Z→qq¯ events collected by the ALEPH experiment during 1991–1995. B0sBs0 candidates are partially reconstructed by combining tracks with fully reconstructed D−sDs− candidates. The B0sBs0 production flavour is estimated from the sign of the opposite hemisphere charge, a fragmentation kaon in the same hemisphere, or a lepton in the opposite hemisphere. From a total sample of 1620 candidates, with a B0sBs0 purity estimated to be 22%, all values of ΔmsΔms below 3.9 ps−1−1 and between 6.5 and 8.8 ps−1−1 are excluded at 95% CL. From the same sample, the B0sBs0 lifetime is measured to be τs=1.47±0.14(stat)±0.08(syst)τs=1.47±0.14(stat)±0.08(syst) ps. This analysis selects mainly hadronic B0sBs0 decays and is statistically independent of a previous ALEPH analysis selecting B0s→D(∗)−sℓ+νBs0→Ds(∗)−ℓ+ν candidates. Combining these two analyses yields Δms>7.9Δms>7.9 ps−1−1 at 95% CL and τs=1.51±0.11τs=1.51±0.11 ps.