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A ultraviolet complete large N thermal QCD model: renormalization group flow and mesonic spectra

The large N thermal Quantum Chromodynamics (QCD) that we study here is a generalization of SU(3) QCD with two gauge groups at high energy scales, i.e. in the ultraviolet (UV). Both gauge groups are related to N as SU(N)×SU(kN) with k < 1. In our construction, we have a model that has a complete UV description, as well as a low energy, i.e. infrared (IR), behaviour that mimicks that of QCD. Our model has three regions. The IR region is the well known cascading model with extensions to include favours. The two gauge groups of this theory reduce to a single SU(kN) group which then confines. The UV region uses congurations from type IIB string theory on the conifold to describe the dynamics. The intermediate region smoothly connects the two, i.e. the UV and the IR, so that we have a complete model for all energy scales. All regions are related to the gauge theory by gauge/gravity duality. In particular, we analyze the renormalization group (RG) flow of the gauge coupling in the effective field theory. We see that it asymptotically approaches a constant at high energies and flows toward permanent confinement as energy scale decreases. In the IR, we obtain the mesonic spectrum by compactifying extra dimensions and analyzing the wave functions in Minkowski space-time. / Cette these etudies la limit N -> ∞ de la theorie chromodynamique quantique avec les deux groupes de jauge SU(N)×SU(kN) avec k < 1. Un modele est popose pour donner un description complete a la fois dans le regime ultraviolet(UV) et infrarouge(IR). Le regime IR concorde avec celui d'un modele de cascade, qui reduit de seule groupe de jaude SU(N) puis confine, tandis que le regime UV correspond a la theorie des cordes de type IIB sur conifold. Le regime UV possede alors une dualite de supergravite/jauge s'inscritvant dans la correspondance AdS/CFT. Dans le regime intermediere, notre molele connecte de maniere reguliere entre IR et UV. Le group de renormalization de la theorie effective est ensuite analyse. Nous comparons les resultats experimentaux en spectre du meson de notre modele das le regime IR.

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.119566
Date January 2013
CreatorsChen, Long
ContributorsKeshav Dasgupta (Internal/Supervisor)
PublisherMcGill University
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Formatapplication/pdf
CoverageMaster of Science (Department of Physics)
RightsAll items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated.
RelationElectronically-submitted theses.

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