We present measurements of partial branching fractions for the inclusive semileptonic decay of B ! Xu` (` = e or ) leading to the determination of the CKM matrix element jVubj. This analysis is based on a sample of 460 million BB events recorded at the (4S) resonance at the BABAR detector. We select B ! Xu` events using the energy spectrum of the lepton (E`) in an event where one of the B-mesons is fully reconstructed. We measure partial branching fractions in restricted regions of the E` spectrum, which are translated into values of jVubj using four theoretical approaches. We calculate the arithmetic mean, using the results from the four theoretical approaches at E` > 1:5 GeV resulting in: jVubj = (4:68+0:31 0:32) 10 3. The analysis presented in this thesis is the rst time a measurement of jVubj has been performed using the E` spectrum in events tagged with a fully reconstructed B meson.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:509645 |
| Date | January 2009 |
| Creators | Sigamani, Michael |
| Publisher | Queen Mary, University of London |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://qmro.qmul.ac.uk/xmlui/handle/123456789/585 |
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