Electron Identification and Measurement of the Inclusive Semileptonic Branching Fraction of B Mesons at the BABAR Experiment
Author | : |
Publisher | : |
Total Pages | : |
Release | : 2002 |
ISBN-10 | : OCLC:652226460 |
ISBN-13 | : |
Rating | : 4/5 ( Downloads) |
Download or read book Electron Identification and Measurement of the Inclusive Semileptonic Branching Fraction of B Mesons at the BABAR Experiment written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An algorithm for identification of electrons with the BABAR detector is developed. Based on pure samples of electrons and hadrons obtained from data, we determine the electron identification efficiency to be above 90% for momenta above 0.5 GeV/c in the laboratory frame, while the pion fake rate lies between 0.05% and 0.1%. Based on this algorithm, a measurement of the inclusive lepton momentum spectrum in B meson decays is performed. We analyze 4.13 fb^-1 and 0.97 fb^-1 of data recorded at and slightly below the Upsilon(4S) resonance with the BABAR detector at the PEP-II a symmetric B-Factory. B-Bbar events are tagged by a high momentum electron. Using charge and angular correlations, leptons from a second semileptonic $B$ decay are separated from secondary charm semileptonic decays. The inclusive branching ratio is measured to be (10.85 +-0.22(stat.) +-0.34(sys))% . Combined with the B lifetime we determine |V_cb| = 0.0406 +-0.0009(exp) +-0.0019(theory).