Determination of |Vub| in inclusive semileptonic B meson decays
Abstract
We present a preliminary determination of the CKM matrix element |Vub| based on the analysis of semileptonic B decays from a sample of 88 million Upsilon(4S) decays collected with the BaBar detector at the e+e- storage ring. Charmless semileptonic B decays are selected using the electron energy E_e and the invariant mass q^2 of the electron-neutrino pair. The neutrino momentum is inferred from a measurement of the visible energy and momentum in the detector and knowledge of the e+e- beam momenta. The partial branching fraction is determined in a region of the q^2-E_e plane where semileptonic B decays to charm are highly suppressed. The total charmless semileptonic branching fraction is extracted using a theoretical calculation based on the heavy quark expansion. Preliminary results yield |Vub| = (4.57 +/- 0.21 +/- 0.25 +/- 0.34 +0.59/-0.29 +/- 0.22) x 10^{-3} where the uncertainties are from statistics (data and MC), detector modeling, background modeling, the shape function, and the heavy quark operator product expansion, respectively.
- Publication:
-
arXiv e-prints
- Pub Date:
- August 2004
- DOI:
- 10.48550/arXiv.hep-ex/0408045
- arXiv:
- arXiv:hep-ex/0408045
- Bibcode:
- 2004hep.ex....8045A
- Keywords:
-
- High Energy Physics - Experiment
- E-Print:
- Document includes 17 pages, 3 figures. Preliminary results to be presented at ICHEP 2004 in Beijing