In this thesis we calculate the symmetric S-state contribution to the binding energy of the triton (H³) using the nucleon-nucleon potentials recently developed by Wong (1965). Towards this end we employ a modification of the equivalent two-body method used by Peshbach-Rubinow (1955). / Science, Faculty of / Physics and Astronomy, Department of / Graduate

The differential cross sections for the production of definite lambda hypernuclear states, within the single scattering, impulse approximation, are calculated from the reaction n(K⁻,π⁻)Λ° on nuclear targets of helium, carbon and oxygen at various K-meson incident momentum. It is shown that these predictions are very sensitive to the three momentum transfer and to the wave function of the bound lambda in the hypernucleus. From the calculations, it is shown that it is possible to observe their production by studying the missing mass spectrum of the emitted pion. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

A basic introduction to the techniques of writing computer simulations for particle physics experiments concerning rare decays is given. A very brief outline of the theoretical basis for cross-section calculations is followed by more in-depth discussions of Monte Carlo sampling techniques, including the use of the CERN package DIVON. The reader is introduced to the concepts involved in detector simulation; specifically, the CERN package GEANT in presented and discussed in some detail. Finally, methods of modelling external conversion processes are taken up. Illustrations for the discussions are taken from the various rare decay modes of the π⁰. Example code and some sample results comparing simulated and real data are given in the appendices. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

The free neutron-proton elastic differential cross section has been measured at neutron beam energies of 212 and 418 MeV. . The experiment determined the angular distribution over the range 15°-180° (CM) in two segments, having the same overall normalization. The 15°-90° range was measured by detecting scattered neutrons in a scintillator and HWPC array. Normalization was obtained by moving the array into the direct neutron beam. Energy selection was made via a time of flight (TOF) measurement relative to the TRIUMF cyclotron RF. The neutron detector was calibrated absolutely using an associated particle technique, in which the recoil proton was detected. The ratio of coincidentally observed neutron-proton pairs to protons alone yielded the efficiency, which was used to calibrate neutron beam monitors. The remainder of the angular distribution was obtained by detecting the scattered protons in a magnetic spectrometer. Proton selection was made using the TOP through the spectrometer and the momentum. Energy selection was made via the BF TOF. Normalization was provided by the same monitors as used in the measurement of the forward half of the angular distribution. The normalization of d?/dΩ has been determined to about 3%, with statistical accuracies of about 1-3% on the individual data points. These data have been included in a phase shift analysis together with all world data, showing an improvement in the energy dependence of the differential cross section near 0° CM and in the phase shifts, notably, E₃. Together with the previously measured Wolfenstein parameters, unambiguous phase shifts in the I=0 system are obtained for the first time in the TRIUMF energy range. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

A separable potential model is constructed to describe the coupled ΣN-AN systems. From this the Σ single particle potential is developed including Pauli effects. The momentum space Schroedinger equation is then solved self-consistently for the complex eigenvalues of 1s and lp state Σ° hypernuclei. Arising from two quite distinct mechanisms these states are all found to be long lived. In s-states, Pauli suppression of the ΣN->AN conversion reduces the widths by as much as 50% from classical estimates in heavy nuclei, and in light nuclei produces widths as small as 1.8 MeV inΣ[sub=o;sup=5]He. In p-states, Pauli effects are relatively unimportant and the strong absorption of the potential creates extremely narrow quasi-bound states in the Σ continuum. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

This thesis presents new interaction potentials for studying systems of nucleons and pions at intermediate energies. Using a quantum field theory approach, the fundamental dynamical variables are taken to be the Fermion and Boson creation operators, F⁺ and B⁺. First, considering systems with only nucleons, a 2-body nucleon interaction potential is introduced, from which the familiar pair of coupled differential equations for the deuteron is derived. Next, turning to systems of nucleons and pions, focusing primarily on the reaction p+p → π⁺+d , we introduce unconventional, penta-linear interaction potentials of the form "F⁺F⁺FFB⁺ + adjoint". With these unconventional potentials, we can identify F⁺10> and B⁺10> with physical nucleons and physical pions— quite unlike the conventional situation with the Chew Hamiltonian, where F⁺10> cannot be identified with a physical nucleon. The differential scattering cross section for pp → π⁺d ( (with polarized incident protons) is then derived in terms of our potentials. Finally, we include a simple perturbation study of the deuteron state using our potentials. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Time-resolved Fourier spectroscopy has been applied to the observation of Rydberg O(I) and O(,2) infrared emission from a pulsed discharge at 0.1 torr. The emission of a 2.5 meter long column through the negative glow was observed with a newly designed discharge apparatus. A computer-controlled interferometer step-servo was developed to enable 100 microsecond time- and 0.12 cm('-1) spectral-resolution capabilities. The Rydberg features were enhanced with respect to those of contaminates by signal processing methods that utilized their individual temporal behavior. Line position determinations of the 7h - 5g, 7g - 5f, 5g - 4f and 6g - 4f O(I) lines have been made to an accuracy of 0.015 cm('-1). Polarization constants of the O(II) core have been deduced from this data. Nine newly observed and four previously observed line-like features have been attributed to Rydberg O(,2).

Precise knowledge of parton distribution functions (PDFs) is necessary to the accurate calculation of QCD observables initiated by hadrons. The deep inelastic scattering (DIS) and lepton pair production (LPP) processes are primary sources of information on PDFs. Recent global fits for PDFs have used DIS data from the large Bjorken $x$, moderate $Q^{2}$ region. It is known that there are large logarithms in this kinematic region that can be resummed using threshold resummation techniques. The purpose of this study is to investigate the effects of simultaneously including DIS and LPP threshold resummation in the determinations of PDFs. The analysis includes a study of the effects of the choice of resummation prescription and of current resummation methods used in the LPP rapidity and $x_{F}$ distributions. It is demonstrated theoretically and phenomenologically that the current resummation methods for such distributions are approximations that lose accuracy at high rapidities or $x_{F}$. The unapproximated resummation formalism is extended to the $\overline{\mathrm{MS}}$ scheme in the minimal and Borel prescriptions and used in conjunction with resummation in DIS to perform a global fit. The resultant PDF sets that correspond to two choices of resummation prescription are analyzed to determine the effect of threshold resummation on PDF fits and its theoretical uncertainties. / A Dissertation submitted to the Department of Physics in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Spring Semester, 2015. / April 1, 2015. / PDF, Prescription, Resummation, Threshold / Includes bibliographical references. / Joseph F. Owens, III, Professor Directing Thesis; Ettore Aldrovandi, University Representative; Laura Reina, Committee Member; Susan Blessing, Committee Member; Winston Roberts, Committee Member.

Bibliography p. 214-226. / Exclusive measurements have been made of the reactions ⁴He(p,2p ), (p,pd), (p,pt) and (p,ph) at 100 MeV. The primary protons were measured at two angles, 45° and 60°, in coincidence with secondary protons, deuterons, tritons or helions covering a wide range of angles on the opposite side of the beam, from -15° to -90° in plane, and from 0° to 30° out-of-plane. The purpose of the experiment was to explore the validity of the Distorted Wave Impulse Approximation (DWIA) as a description of these quasifree knockout reactions, at all geometries where the knockout cross section is significant. Six particle telescopes, each consisting of two silicon detectors and a NaI detector, were used to measure the coincident particles. The experimental data are presented in the form of energy-sharing distributions, which were generated by projecting the two-dimensional quasifree knockout loci onto the energy axis of the primary proton. The comparison between these energy-sharing distributions and the curves calculated by means of the DWIA is satisfactory for all geometries, except at the most forward secondary angles for the (p,pt) and (p,ph) reactions. It is concluded that the DWIA is an adequate formalism for modelling the quasifree knockout reactions induced by 100 MeV protons on ⁴He. Based on this conclusion, the total contribution of quasifree knockout to the existing inclusive (p,p') spectra has been calculated by integrating the DWIA cross sections over the solid angles of the secondary particles. The spectroscopic factors used were those extracted from the coincidence data. For the (p,pn) reaction, it was assumed that the spectroscopic factors were the same as for (p,2p). It is found that 70 ± 10% of the inclusive continuum yields is attributable to quasifree scattering, with ~30% arising from multiple scattering. At low energies of the scattered proton, the knockout of nucleons constitutes over 90% of the quasifree component, whereas at high energies the knockout of deuterons, tritons and helions dominates the yield. Thus the absence of discernable quasifree peaks in the inclusive spectra is probably due to the cluster knockout contributions filling in the yield at higher energies.

The production of direct photons in association with jets can be used to probe gluon parton distribution functions as well as to test perturbative Quantum Chromodynamics. This thesis presents the measurement of the triple differential cross section for photon plus jet evehts as a function of photon transverse momentum (pɣT), photon pseudorapidity (ηɣ), and jet pseudorapidity (ηjet). The measurement is made using 19.7 fb⁻¹ of data collected by the Compact Muon Solenoid detector in proton-proton collisions at the center-of-mass energy of 8 TeV. The kinematic regions probed are 40 [less than] pɣT [less than] 1000 GeV, |ηɣ| [less than] 2.5 and |ηjet| [less than] 2.5. These results are compared to next-to-leading order theoretical predictions. / A Dissertation submitted to the Department of Physics in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Summer Semester 2016. / June 3, 2016. / Includes bibliographical references. / Andrew Askew, Professor Co-Directing Dissertation; Susan Blessing, Professor Co-Directing Dissertation; Qing-Xiang Sang, University Representative; Todd Adams, Committee Member; Joseph Owens, Committee Member; Jorge Piekarewicz, Committee Member.