Determination of |Vub| from the measurement of the inclusive charmless semileptonic branching ratio of b hadrons

• Main Authors: BARATE, R., THULASIDAS, M.
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 1999
• Subjects: Computer Sciences; Databases and Information Systems
• Online Access: https://ink.library.smu.edu.sg/sis_research/5842; https://ink.library.smu.edu.sg/context/sis_research/article/6845/viewcontent/ep_98_067.pdf
• Institution: Singapore Management University

From a study of the kinematic properties of the final state produced in the semileptonic decays b→Xℓνℓb→Xℓνℓ, 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→Xuℓνℓ)Br(b→Xuℓνℓ) is determined to be (1.73±0.55stat±0.55syst)×10−3(1.73±0.55stat±0.55syst)×10−3, where XuXu represents any charmless hadronic state and b is a mixture of b hadrons weighted by their production rates. This measurement yields the result|Vub|2=(18.68±5.94stat±5.94syst±1.45HQE)×10−6,|Vub|2=(18.68±5.94stat±5.94syst±1.45HQE)×10−6,where the last error comes from the conversion of the branching ratio to the CKM matrix element squared.