Fragmentation is the process by which bare quarks dress themselves up as hadrons. Since we cannot get reliable calculations of this process using perturbative quantum chromodynamics, the fragmentation properties of quarks must be obtained empirically. We report on the signal extraction and relative transverse momentum (pT) spectrum determination that will lead to a high precision measurement of relative fragmentation fractions of b quarks into B hadrons, in 1.96 TeV pp¯ collisions. Using 1.9 fb-1 of data taken with the CDF-II detector, we fully reconstruct 473 +/- 42 B0s→D-sp + , 15206 +/- 203 B0 → D-pi+, 1483 +/- 45 B0 → D*-pi + and 4444 +/- 297 L0b→L+ cp- candidate decays. In order to reduce systematic uncertainties, ratios of pT spectra are reported. We find that Bs and B0 mesons are produced with similar pT and Λb baryons are produced with lower pT than B0 mesons. Our results are consistent with previous CDF measurements suggesting a difference between fragmentation processes observed at lepton and hadron colliders.

Thesis (Ph. D.)--University of Hawaii at Manoa, 1995. / Includes bibliographical references (leaves 82-85). / Microfiche. / xi, 85 leaves, bound ill. 29 cm

The study of scattering amplitudes beyond one loop is necessary for precision phenomenology for the Large Hadron Collider and may also provide deeper insights into the theoretical foundations of quantum field theory. In this thesis we develop a new method for computing two-loop amplitudes, based on unitarity rather than Feynman diagrams. In this approach, the two-loop amplitude is first expanded in a linearly independent basis of integrals. The process dependence thereby resides in the coefficients of the integrals. These expansion coefficients are then the object of calculation. Our main results include explicit formulas for a subset of the integral coefficients, expressing them as products of tree-level amplitudes integrated over specific contours in the complex plane. We give a general selection principle for determining these contours. This principle is then applied to obtain the coefficients of integrals with the topology of a double box. We show that, for four-particle scattering, each double-box integral in the two-loop basis is associated with a uniquely defined complex contour, referred to as its master contour. We provide a classification of the solutions to setting all propagators of the general double-box integral on-shell. Depending on the number of external momenta at the vertices of the graph, these solutions are given as a chain of pointwise intersecting Riemann spheres, or a torus. This classification is needed to define master contours for amplitudes with arbitrary multiplicities. We point out that a basis of two-loop integrals with as many infrared finite elements as possible allows substantial technical simplications, in terms of obtaining the coefficients of the integrals, as well as for the analytic evaluation of the integrals themselves. We compute two such integrals at four points, obtaining remarkably compact expressions. Finally, we provide a check on a recently developed recursion relation for the all-loop integrand of the amplitudes of N=4 supersymmetric Yang-Mills theory, examining the two-loop six-gluon MHV amplitude and finding agreement. The validity of the approach to two-loop amplitudes developed in this thesis extends to all four-dimensional gauge theories, in particular QCD. The approach is suited for obtaining compact analytical expressions as well as for numerical implementations.

Bibliography: p. 169-172. / viii, 172 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Uses the tool of lattice regularisation to calculate the 2-point Euclidean Green's function in pure SU (3) Yang-Mills (quenched quantum chromodynamics), in Landau gauge. Adding improved gauge fixing and tree level correction to the improvement program developed by Symanzik [et al.], shows that the gluon propagator can be reliably calculated on lattices coarser than has hitherto been used. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 2000?

Bibliography: p. 169-172. / viii, 172 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Uses the tool of lattice regularisation to calculate the 2-point Euclidean Green's function in pure SU (3) Yang-Mills (quenched quantum chromodynamics), in Landau gauge. Adding improved gauge fixing and tree level correction to the improvement program developed by Symanzik [et al.], shows that the gluon propagator can be reliably calculated on lattices coarser than has hitherto been used. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 2000?

Title page, abstract and table of contents only. The complete thesis in print form is available from the University of Adelaide Library. / This thesis investigates the spectrum of baryon resonances in quenched lattice QCD. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1277637 / Thesis (Ph.D.) -- University of Adelaide, School of Chemistry and Physics, 2007

Title page, abstract and table of contents only. The complete thesis in print form is available from the University of Adelaide Library. / This thesis investigates the spectrum of baryon resonances in quenched lattice QCD. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1277637 / Thesis (Ph.D.) -- University of Adelaide, School of Chemistry and Physics, 2007

Thesis (Ph. D.)--University of Adelaide, 1988. / Typescript. Copies of three papers (2 published), co-authored by the author, in back. Includes bibliographical references (leaves 179-186).

Thesis (Ph.D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 2000? / Bibliography: p. 169-172.

Thesis (Ph.D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 2002. / Bibliography: p. 156-162. Chronological list of the author's works: p. 155.