Supersymmetric extensions to the Standard Model (SM) have many interesting experimental consequences which can provide important hints to the physics beyond the SM. In this thesis, we first study the anomalous magnetic moment of the muon and show that a significant constraint on the parameter space can be obtained from its current experimental value. In the next topic, we study the CP violations in B -> phi K decays and show that the SM and the minimal supergravity model (mSUGRA) cannot account for the current experimental observation. We then show that all the data can be accommodated for a wide range of parameters in models with non-universal soft breaking left-right A terms. In our last topic, which is based on a Horava-Witten inspired model proposed by R. Arnowitt and B. Dutta, we extend their analysis to the full fermion sector of the SM and propose a new mechanism different from the usual see saw mechanism to generate small neutrino masses which are in good agreement with the current neutrino oscillation data.

Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Physics and Astronomy." Includes bibliographical references (p. 93-97).

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Much of the low energy phenomenology which can be extracted from the field theory limit of the intrinsically ten dimensional E 8 ® E 8 heterotic superstring depends upon the topological and geometrical properties of the six dimensional compactified component of spacetime. After briefly reviewing the topological constraints on the latter manifold which ensure the survival of N=l four dimensional supersymmetry, we present and apply the mathematics necessary for the rigorous construction of vacuum solutions and the determination of the four dimensional massless field content. Two phenomenologically attractive classes of solutions, with unbroken E₈ ⨂ SU(5) and E₈ ⨂ SO(10) gauge groups, arise if the vacuum configuration contains a Ricci flat Kahler manifold with SU(3) holonomy (Calabi-Yau manifold), which admits certain SU(5) or SU(4) vector bundles. Further reduction of the gauge group and emergence of naturally light weak Higgs doublets may also occur by flux breaking if the Calabi Yau manifold is multiply connected. We analyse the feasibility of such scenarios for Calabi Yau manifolds with any possible fundamental group. Phenomenological considerations place severe constraints on the dimensions and transformation properties of certain cohomology groups and thereby lead to a highly restricted class of acceptable models. We then present the mathematical analysis of a three generation heterotic superstring inspired model, with E₈ ⨂ E₆ gauge symmetry. A detailed description of the manifold of compactification is given, along with a determination of its Hodge numbers and of the associated light supermultiplet structure. For a particular choice of vacuum moduli we derive this manifold's symmetry group, and determine its action on the massless fields in the theory. Preliminary investigation indicates that these transformation properties give rise to a remarkably realistic model. In the second volume we derive cosmological constraints on a supersymmetric extension of the standard model in which weak gauge symmery breaking is triggered at the tree level by a Higgs singlet superfield. The fermionic component of this gauge singlet (the "nino") is shown to be the lightest supersymmetric particle with a relic abundance near the critical closure density for a surprisingly wide range of the unconstrained parameters. The previously favoured photino dark matter scenario has been eliminated by the non observation of high energy solar neutrinos. After briefly reviewing this argument, we extend the analysis to eliminate Higgsino dark matter scenarios with and#60H₁°and#62 ≠ and#60H₂°and#62. We show that the nino produces an acceptably low level of solar neutrinos and that it may also account for the anomalously high level of cosmic ray antiproton flux.

Thesis (Ph. D.)--University of Oregon, 2007. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 130-131). Also available for download via the World Wide Web; free to University of Oregon users.

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 74-76). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--Northeastern University, 2009. / Title from title page (viewed June 22, 2009). Graduate School of Arts and Sciences, Dept. of Physics. Includes bibliographical references (p. 163-178).

Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Physics and Astronomy." Includes bibliographical references (p. 92-96).

Made available in DSpace on 2016-05-17T16:51:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-12-12. Added 1 bitstream(s) on 2016-05-17T16:54:20Z : No. of bitstreams: 1 000856021.pdf: 568941 bytes, checksum: 27225bb39374c43fe746302ce9bcbbe7 (MD5) / Nesta tese, mostramos o cálculo da função de partição dos espinores puros. O cálculo será executado de dois modos diferentes usando o método de fantasma-para-fantasma (até o décimo segundo nível massivo) e usando o método do ponto fixo (até o quinto nível massivo). Após incluir a contribuição das variáveis do setor da matéria ('qui POT. m, 'teta POT. alfa', 'rô IND. alfa'), nós derivamos o espectro massivo da supercorda aberta. Embora os espinores puros sejam variáveis bosônicas, a função de partição dos espinores puros contém estados fermiônicos os quais começam aparecer a partir do segundo nível massivo. Estes estados fermiônicos vêm de funções que não são bem definidas globalmente no espaço dos espinores puros, e estão relacionados ao fantasma b no formalismo de spinores puros para a supercorda / In this thesis, we have calculated the partition function of pure spinors. The computation is performed by using two different methods, namely ghosts-for-ghosts (up to the twelth mass-level) and fixed point (up to the fifth mass-level) techniques. After adding the contribution from the ('qui POT. m, 'teta POT. alfa', 'rô IND. alfa') matter variables, we reproduce the massive open superstring spectrum. Even though pure spinor variables are bosonic, the pure spinor partition function contains fermionic states which first appear at the second mass-level. These fermionic states come from functions which are not globally defined in pure spinor space, and are related to the b ghost in the pure spinor formalism for the superstring