The precise determination of the CKM matrix element |Vub| is crucial in testing the Standard Model mechanism for CP violation. From a sample of 88 million BB pairs collected with the MBAR detector, charmless semileptonic B decays are selected using simultaneous requirements on the electron energy, Ee, and the invariant mass squared of the electron-neutrino pair, q2. The partial branching fraction, unfolded for detector effects, is determined in a region of the q2-Ee plane where the dominating semileptonic decays to charm mesons are highly suppressed. Theoretical calculations based on the Heavy Quark Expansion allows for a determination of |Vub| = (3.95 ± 0.27 +0.58 -0:42 ± 0.25) x 10 3, where the errors represent experimental, heavy quark parameters and theoretical uncertainties, respectively.
| Identifer | oai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/1971 |
| Date | 14 December 2009 |
| Creators | Fortin, Domininque |
| Contributors | Kowalewski, Robert |
| Source Sets | University of Victoria |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | Available to the World Wide Web |
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