STUDIES OF Bs PRODUCTION AND SEMILEPTONIC DECAY, AND OF ANTIDEUTERON PRODUCTION IN Υ DECAY AND QUARK FRAGMENTATION AT BABAR

Title of dissertation: STUDIES OF Bs PRODUCTION AND SEMILEPTONIC DECAY, AND OF ANTIDEUTERON PRODUCTION IN Υ DECAY AND QUARK FRAGMENTATION AT BABAR Brian Hamilton, Doctor of Philosophy, 2012 Dissertation directed by: Professor Abolhassan Jawahery Department of Physics I present a measurement of the inclusive semileptonic branching fraction of the Bs meson and Bs production rates relative to all B mesons using a data set collected with the BABAR detector at the PEP-II asymmetric energy electron-positron collider operating at center-of-mass energies above the Υ (4S) resonance. The quantities are extracted simultaneously using inclusive yields of φ mesons and φ mesons in coincidence with a high momentum lepton. The Bs semileptonic branching fraction is found to be B(Bs → lνX) = 9.5 −2.0−1.9, where the first uncertainty is statistical and the second is systematic. Additionally, I present measurements of antideuteron production using the BABAR data collected at collision center-of-mass energies corresponding to the masses of the Υ (2S), Υ (3S), and Υ (4S) resonances. Measurements of specific ionization for charged tracks in the BABAR detector are used to obtain the antideuteron production rate in decays of the Υ (1S), Υ (2S), and Υ (3S) resonances as well as in continuum ee annihilation to hadrons. The total rates observed in the data are B(Υ (2S) → d̄X) = (2.62 ± 0.10 −0.28) × 10, B(Υ (1S) → d̄X) = (2.85± 0.47 −0.29)× 10, B(Υ (3S) → d̄X) = (2.45± 0.14 −0.24)× 10, and the cross section for antideuteron production in continuum ee annihilation is found to be σ(ee(10.58GeV) → dX) = (10.49 ± 0.33 −1.14) fb. No significant production in Υ (4S) decays is observed. STUDIES OF Bs PRODUCTION AND SEMILEPTONIC DECAY, AND OF ANTIDEUTERON PRODUCTION IN Υ DECAY AND QARK FRAGMENTATION AT BABAR by Brian Keith Hamilton Dissertation submitted to the Faculty of the Graduate School of the University of Maryland, College Park in partial fulfillment of the requirements for the degree of Doctor of Philosophy 2012 Advisory Committee: Professor Abolhassan Jawahery, Chair/Advisor, Associate Professor Zackaria Chacko, Professor Michael Coplan, Professor Nick Hadley, Associate Professor Douglas Roberts c © Copyright by Brian Keith Hamilton 2012