THEORETICAL PHYSICS

Author: Roca Zamora Luis.
Year: 2004.
University: VALENCIA.
Place of defense: Facultad de Fisica.
Place of preparation: Facultad de Fisica.

Summary: The main objective of this thesis is to implement results of the unit extensions of the theory of chiral disruptions in specific processes of decay and production of resonances hadrónicas. The great wealth and virtue of the theory is that many resonances (particularly inns scalar) are dynamically generated based solely on the Lagrangianos lower order of perturbation theory chirality and implemented unitariedad channels trailers and exploiting properties analiticidad THE RANGES dispersion. In other words, many resonances arise dynamically without the need to enter them as explicit degrees of freedom. The reactions we have been studied eta -- higher than pi0pi0gamma, phi -- higher than PPgamma yJ/Psi- higher than VPP. With the inclusion of mecnaismos relevant and implentando interaction final statement inns pseudosclaraes through techniques chiral unit have obtained a good description of the processes considered explaining the important role played by scalar inns in its internal dynamics. On the other hand, using the techniques chiral unit we got that inns axial-vector smaller mass have a large component of origin through dynamic interaction octete vector pseudoscalres with the vectors. In the second part of the thesis, we have studied the feasibility of observing the change in the properties of nuclear resonances citations (sigma rho and phi) reactions using specific production kernels. Using fotoproducción two piones in nuclei that we saw in this reaction shows an corriemiento of intensiad in more invariant d elos two piones toward low massa invariant because of the decline in the mass of meson sigam. In the case of rho observe a small effect due to the strong absorption of piones means that the reaction is very peripheral. In the case of phi propose a reaction that can be viable observe for the first time the modification of the width of phi in the middle through the study of the absorption flow phis produced in nuclei.

Author: González Cámara Pablo Andrés.
Year: 2005.
University: AUTÓNOMA DE MADRID.
Place of defense: Departameno de Física Teórica.
Place of preparation: Universidad Autónoma de Madrid.

Summary: The search for a unified theory of fundamental particles and their interactions has culminated in the last two decades with the spectacular development of string theory. This reconcile general relativity with quantum mechanics and contains the main ingredients of the Standard Model of Particle Physics. To make direct contact with the experiments we have yet to know the precise manner in which the Standard Model and Einstein gravity are embedded in the low energy limit of the theory. This is a broad sense is the main theme of the thesis. A specific aspect of compactificaciones string that has recently received special attention is the possibility of including flows antisymmetric not trivial. The compactificaciones in the presence of streams presents some novel features that make them particularly interesting: continuous certain parameters (moduli) are stabilized, limiting the arbitrariness of emptiness and inducing words' soft 'breaking of supersymmetry in the volume of D-branas where resides matter content of the Standard Model. The objective of this thesis is to combine the compactificaciones theory of strings that lead to a spectrum close to the Standard Model with compactificaciones in the presence of streams. In particular, the main goal is to determine what moduli of the compactificación are stabilized by flows and what kind of terms' soft 'lead, providing some specific examples. Thus, first discusses some of the basic rules for the construction of models D-branas and plans orientifold, providing some specific examples. Then enter flows in a orientifold toroidal and explores the potential partner, focusing on the study of the critical points. The potential has to respect certain symmetries of string theory (double S), conjeturándose thus the existence of new sets of traffic (not geometric). Finally, it examines the impact of the flows that break supersymmetry in the volume of D-branas, showing concodancia with predictions obtained supergravity.

Author: GARCÍA TORMO XAVIER.
Year: 2005.
University: BARCELONA.
Place of defense: FACULTAD DE FÍSICA.
Place of preparation: FACULTAT DE FÍSICA.

Summary: The thesis deals with the study of the structure and interactions of the basic constituent of matter. Within the framework of quantum field theory, using techniques known by the generic name of Theories Effectives to study the heavy quark sector of the standard model of fundamental interactions. The thesis focuses particularly, though not exclusively, on systems quarkonium heavy (states linked by two heavy quark). More specifically, the thesis contains a study of the dependence infrared sub-dominante potential static singlet of quantum chromodynamics, a study of currents quark ligero-a-pesado in the effective theory known as Soft-Collinera Effective Theory (at dominant the parameter expansion theory effective), and finally the tesión also contains an extensive study of the decay radioactive semi-inclusivas of quarkonium heavy.

Author: PERALTA SALAS DANIEL.
Year: 2005.
University: COMPLUTENSE DE MADRID.
Place of defense: FACULTAD DE CIENCIAS FÍSICAS.
Place of preparation: FACULTAD DE CIENCIAS FÍSICAS.

Summary: The thesis is obtained mixed results on comprehensive and joint invaginares field vector, usually analytical, Rn. The properties under consideration are basically the stability of critical points and when solutions are known integral first, the relationship between symmetries, first and joint invariant integrals, and the existence of joint atractores invariants. These results are of interest primarily mathematician. The thesis also provides applications to different physical contexts, including equations of Newtonian mechanics, magnetic fields created by threads and fields Lotka-Volterra.

Author: ENCISO CARRASCO ALBERTO.
Year: 2006.
University: COMPLUTENSE DE MADRID.
Place of defense: FACULTAD DE CIENCIAS FÍSICAS.
Place of preparation: FACULTAD DE CIENCIAS FÍSICAS.

Summary: The thesis examines the relationship between the models of N bodies with spin rate Calogero-Sutherland and chains spins built. First, it calculates the exact spectrum of the chain Haldane-Shastry type NCB through a rigorous treatment of the mechanism of freezing Polychronakos. Subsequently explores systems of N bodies with spin interaction with nearby neighbors through a non-trivial modification of the formalism of operators Dunkl. These quantum systems, which can be seen as cyclical versions of the model Calogero-Sutherland usual, causing chains spins cuasi-exactamente soluble through the mechanism of freezing. Detailed analysis of one of these chains took the last part of the thesis.

Author: BAE JOONWOO.
Year: 2006.
University: BARCELONA.
Place of defense: FACULTAD DE FÍSICA.
Place of preparation: FACULTAD DE FÍSICA, UNIVERSIDAD DE BARCELONA.