Heavy Flavour Physics from Lattice QCD.
Abstract
Available from UMI in association with The British Library. We study the semileptonic and nonleptonic decays of charmed D mesons. In the semileptonic case, using the lattice conserved current, we compute the form factors f_0 and f_+ at q^2 = 0 and show them to be in good agreement with experimental observations. Nearest pole dominance gives a good description of the form factors for those points for which our calculations are reliable. The dependence of the conserved current matrix elements with the light quark mass is investigated. Computations using the local current are also performed. After renormalization, results are consistent with experiment, but not in such good agreement as the conserved current calculations. For nonleptonic decays into two pseudoscalar particles, final state interactions are shown to be negligible in our computations. We find that the lattice amplitudes of the various decay channels have large statistical errors and display a heavy dependence on the light quark mass. No clear information can be extracted. Following a method proposed in Nucl. Phys. B(Proc. Suppl.)4 1988:170 by E. Eichten, we investigate the treatment of heavy quarks on the lattice by calculating the B meson decay constant. The results show that it is necessary to have a statistical sample much greater than for similar calculations with light quarks to achieve comparable precision. Computations are carried out on a 20 x 10 x 10 x 40 lattice at beta = 6.0 using Wilson fermions in the Quenched approximation.
 Publication:

Ph.D. Thesis
 Pub Date:
 1989
 Bibcode:
 1989PhDT.......209H
 Keywords:

 Physics: Elementary Particles and High Energy