Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references. Available also from UMI/Dissertation Abstracts International.

Not available / text

First, we review the basics of baryogenesis and models for baryogenesis in the early literature. Then, we discuss the main theme in this thesis, electroweak baryogenesis, which utilizes the electroweak phase transition. We present how the phase transition can be used to achieve baryogenesis. Next, we develop our model, which is the Standard Model with a singlet field coupled to the Higgs doublet negatively and to the right-handed neutrinos. It is a simple extension of the singlet Majoron model. We focus on numerical analysis of the model. Parameter space satisfying all the conditions are found and relevant quantities, such as the critical temperature, the Higgs mass, and the mixing angle are found as well. It turns out that LEP bound on the Higgs mass and the mixing angle is a strong constraint, and only a small fraction of parameter space is acceptable for attaining a strong enough phase transition for baryogenesis.

We determine the energy spectrum of the baryons by treating each of them as a three-body system with the interacting forces coming from a set of two-body potentials that depend on both the distance between the quarks and the spin and orbital angular momentum coupling terms. We first review constraint dynamics for a relativistic two-body system in order to assemble the necessary two body framework for the three-body problem. We review the different types of covariant two-body interactions involved in constraint dynamics, including vector and scalar, and solve the problem of energy eigenstates using constraint dynamics. We use the Two Body Dirac equations of constraint dynamics derived by Crater and Van Alstine, matched with the quasipotential formalism of Todorov as the underlying two-body formalism. We then use the three-body constraint formalism of Sazdjian to integrate the three two-body equations into a single relativistically covariant three body equation for the bound state energies. The results are analyzed and compared to experiment using a best fit method and several different algorithms, including a gradient approach, and Monte Carlo method.

Thesis (Ph. D.)--University of Hawaii at Manoa, 1995. / Includes bibliographical references. / Microfiche. / xii, 148 leaves, bound ill. 29 cm

Thesis (Ph.D.)--Duke University, 2009.

No description available.

Plusieurs observations montrent une asymétrie baryons-antibaryons dans l'Univers. La principale théorie expliquant cette asymétrie est la baryogenèse qui requiert les trois conditions de Sakharov : la non-conservation du nombre baryonique, la présence de violation CP et des interactions entre particules hors de l'équilibre thermique. La baryogenèse nécessite de considérer de la physique au-delà du Modèle Standard (MS), car le MS suppose généralement une asymétrie baryonique trop petite. La baryogenèse peut être obtenue à partir de la leptogenèse, la théorie équivalente pour les leptons. De nouvelles particules et interactions impliquant des leptons généreraient une asymétrie leptonique (AL) mesurable au LHC qui serait transférable au secteur baryonique. L'ajout de neutrinos de chiralité droite (RH) au MS est un choix naturel pour expliquer l'origine de la masse des neutrinos et l'existence d'une AL, et donc d'une asymétrie baryonique. Le projet aborde certains processus détectables au LHC impliquant la désintégration de bosons W en neutrinos RH. Ces processus peuvent violer le nombre leptonique et la symétrie CP. Des facteurs d'asymétrie CP sont calculés et permettent de mesurer des invariants CP. Les invariants CP dépendent des paramètres du modèle et quantifient la violation CP. Ces invariants CP apparaissent dans les équations de Boltzmann qui décrivent l'évolution de l'AL. La résolution de ces équations permet de calculer le ratio du nombre de baryons sur le nombre de photons dans l'Univers. L'identification des invariants CP qui décrivent l'AL permet de tester les modèles de la leptogenèse par la mesure de processus impliquant de la violation CP au LHC. Pour répondre à ces objectifs, un scénario de leptogenèse résonante a été testé. Les résultats obtenus montrent que les invariants CP nécessaires pour reproduire l'asymétrie baryonique sont trop petits pour être mesurés au LHC. De futures recherches pourraient s'intéresser à d'autres modèles menant à un signal observable au LHC.

In this dissertation, we investigate weak lensing cosmology and its astrophysical systematics by employing machine learning techniques. We focus on addressing the discrepancy between two previous weak lensing analyses on CFHTLenS data, understanding the impact of baryons on weak lensing statistics, and leveraging convolutional neural networks (CNNs) for constraining cosmological and baryonic parameters. First, we perform a side-by-side comparison of the two-point correlation function and power spectrum analyses on CFHTLenS data, identifying excess power in the data on small scales and discussing potential origins of this excess power. Next, we study the effect of baryons on weak lensing statistics using the baryonic correction model, demonstrating that marginalizing over baryonic parameters will degrade constraints in the Ωm–σ8 parameter space, but the degradation can be mitigated by combining the lensing power spectrum and peak counts. Second, we explore the use of CNNs to constrain cosmological and baryonic parameters. We find that CNNs can achieve tighter constraints in Ωm–σ8 space than traditional methods on simulation data. We then apply our pipeline to the HSC first-year weak lensing shear catalog. We find that statistical uncertainties of the parameters by the CNNs are smaller than those from the power spectrum and peak counts, showing that CNNs can extract additional cosmological information from weak lensing data even in a real experiment.

The K⁰, K*(892), p⁰(770) and Φ(1020) mesons along with the Λ° baryon have been observed in the TRISTAN energy region of 50 to 61.4 GeV using a data sample of 245.4 pb⁻¹. Their multiplicities and total cross sections are found and compared with the results from experiments at other center-of-mass energies. The multiplicities are compared with various theoretical and phenomenological models. The differential cross sections for the K⁰ and Λ⁰ are calculated and compared with other experiments. Measurements of the ratio of production of vector mesons to vector plus pseudoscalar mesons and the ratio of the production of excited ss̄ quark pairs to the production of excited uū plus dd̄ quark pairs are compared with other experiments along with the phenomenological predictions. The HERWIG Monte Carlo is tuned with regard to the inclusive production of hadrons. / Ph. D.