2004/08/12 by B. Aubert, The BaBar Collaboration, The BABAR Collaboration +2
Engineering · Physics and Astronomy · #Neutrino Physics Research #Particle accelerators and beam dynamics #Particle physics theoretical and experimental studies #hep-ex
paper · pdf · doi:10.48550/arxiv.hep-ex/0408045
Document includes 17 pages, 3 figures. Preliminary results to be presented at ICHEP 2004 in Beijing
arxiv created 2004/08/12 · arxiv updated 2009/12/01
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 Ee and the invariant mass q2 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 q2-Ee 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.