• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 32
  • 5
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 43
  • 43
  • 43
  • 43
  • 15
  • 11
  • 9
  • 8
  • 8
  • 8
  • 6
  • 6
  • 6
  • 6
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Electroweak phase transition and singlet Majoron model

Yamashita, Hiroki, 1981- January 2007 (has links)
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.
12

On a dynamical origin for fermion generations /

Bashford, James Donald. January 2003 (has links) (PDF)
Thesis (Ph.D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 2003. / "July 2003" Bibliography: leaves 101-107.
13

A measurement of the branching fraction of the Ds meson to a muon and a neutrino /

Putz, John Yuri, January 1999 (has links)
Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (p. 100-102).
14

New techniques for measuring atomic parity violation /

Cronin, Alexander D., January 1999 (has links)
Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 219-226).
15

Electroweak scale neutrinos

Díaz Méndez, Enrique. January 2009 (has links)
Thesis (M.S.)--University of Texas at El Paso, 2009. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.
16

Evidence for electroweak top quark production in proton-antiproton collisions at sqrt(s) = 1.96 TeV /

Gadfort, Thomas, January 2007 (has links)
Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 163-169).
17

Construction, testing, and characterization of vertical drift chambers for Qweak /

Dean, Douglas C. January 2009 (has links)
Thesis (Honors)--College of William and Mary, 2009. / Includes bibliographical references (p. 54-55). Also available via the World Wide Web.
18

Beyond the standard cosmological paradigm with weak gravitational lensing

Leonard, Catherine Danielle Bartlett January 2016 (has links)
Next-generation cosmological surveys will demand an unprecedented understanding of the interplay between theoretical and observational aspects of weak gravitational lensing. This thesis presents a study of the parameter degeneracies and theoretical uncertainties which will affect weak lensing tests of cosmology beyond the standard paradigm. In particular, tests of alternative theories of gravity and of spatial curvature are considered. First, by considering linear-order departures from the standard gravitational theory of general relativity, a novel expression is derived for the weak lensing convergence power spectrum under alternative theories of gravity. Using this expression, degeneracies between gravitational parameters in weak lensing observations are explored, first with a focus on scale-independent parameterisations of gravity, then considering new physical scales introduced by alternative theories. The degeneracy-breaking offered by the combination of weak lensing and redshift-space distortions is shown to be robust to the time-dependence of the functions parameterising modified gravity. Next, the gravity-testing statistic EG is investigated, and a new theoretical expression for its observationally-motivated definition is presented. The theoretical uncertainty of EG is compared to forecast statistical errors, and found to be significant in the case of a more futuristic measurement. Predictions are then computed for EG under deviations from general relativity, and the ongoing utility of EG as a probe of gravity is discussed. Finally, an investigation is made of the potential for measuring or constraining the spatial curvature using weak lensing and complementary observables. The predicted constraint on the spatial curvature is forecast for a suite of upcoming surveys, and the effect of including parameters which may be degenerate with the spatial curvature is explored. It is found that upcoming observations are likely to constrain spatial curvature at a 10⁻³ level, but not to reach the best-case constraint of ~10⁻⁴.
19

Beyond the standard cosmological model : dark energy, massive neutrinos and statistical isotropy

Zunckel, Caroline Louise January 2008 (has links)
No description available.
20

New physics from warped compact extra dimensions: from model building to colliders signals

Oliveira, Alexandra Carvalho Antunes de [UNESP] 03 June 2014 (has links) (PDF)
Made available in DSpace on 2015-09-17T15:24:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-06-03. Added 1 bitstream(s) on 2015-09-17T15:47:50Z : No. of bitstreams: 1 000837676.pdf: 5906522 bytes, checksum: 4d7d813fa9837e6b5a068271f434ec38 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / No Modelo Padrão que descreve a física das partículas elementares e suas interações o campo de Higgs pode ser imaginado como um campo composto formado por uma força forte ainda desconhecida. Tal hípótese é bastante atrativa para completar o Modelo Padrão a altas energias. Problemas como hierarquia e naturalidade podem ser mais facilmente evitados. No contexto de uma força forte porém métodos de cálculo baseados em expansões perturbativas não tem mais validade. Uma alternativa para entender as propriedades básicas desse tipo de teoria é trabalhar em termos de teorias de gravitacão com dimensões extras. Nesta tese focamos no caso de uma dimensão espacial extra. Características genéricas desse tipo de cenário são a existência de partículas de gravidade massivas, associadas com a métrica penta-dimensional que acopla com o Modelo Padrão para matéria, levando a assinaturas diretas em colisores de partículas (como o LHC no CERN). Tais partículas de gravidade se acoplam com o setor de Higgs. A descoberta do bóson de higgs abriu um novo camp o de investigação para sua detecção direta, no estado final com dois bósons de higgs. Nós usamos técnicas de Monte Carlo para estudar as estratégias de análise que levariam a um melhor reconhecimento de novas ressonâncias que decaem em pares de bósons de higgs em colisores hadrônicos, que podem ser interpretadas como partículas de gravidade massivas. Finalmente apresentamos as buscas experimentais por tais ressonâncias realizadas no contexto do experimento CMS com dados retirados do primeiro run do LHC (com uma energia de centro de massa de 8 TeV) / The Higgs field of the Standard Model theory for elementary particles and interactions can be realized as a composite state from an underlying strong sector. Such hypothesis is very attractive as an ultraviolet completion of the Standard Model since it solves the hierarchy and avoids naturalness problems. The standard perturbative methods cannot be used in the context of strongly interacting theories, however thyose can be broadly describes in terms of extra dimensional models of gravity. We focus on the case of one additional Warped compact Extra Dimension (WED). The generic signatures of this scenario are the manifestation of heavy gravity particles, associated with the five dimensional metric, that couples with the Standard Model matter leading to direct collider signatures. The heavy gravity particles couples to the Higgs sector. The Higgs discovery had oponed a new investigation channel to LHC direct detection that is the di-higgs final state. We use Monte Carlo techniques to study the analysis strategies that would lead to a best recognition of new resonances decaying to a pair of higgses in hadron colliders, that can be interprets as the gravity particles. We finally present resonance searches performed with data taken by the CMS experiment on the 8 TeV LHC run. The results are interpreted as the gravity particles signatures in the WED context / CNPq: 141964/2009-0

Page generated in 0.0831 seconds