1. Departamento de Física de Altas Energías, - Elena Cáceres; Alberto Güijosa; Bernal Díaz Del Castillo
ABSTRACT: Following recent developments, we employ the AdS/CFT correspondence to determine the drag force exerted on an external quark that moves through an N = 4 super-Yang-Mills plasma with a non-zero R-charge density (or, equivalently, a non-zero chemical potential). We find that the drag force is larger than in the case where the plasma is neutral, but the dependence on the charge is non-monotonic. UTTG-07-06 ICN-UNAM-06/05G

2. Departamento de Física de Altas Energías, - Elena Cáceres; Alberto Güijosa; Bernal Díaz Del Castillo
ABSTRACT: Following recent developments, we employ the AdS/CFT correspondence to determine the drag force exerted on an external quark that moves through an N = 4 super-Yang-Mills plasma with a non-zero R-charge density (or, equivalently, a non-zero chemical potential). We find that the drag force is larger than in the case where the plasma is neutral. UTTG-07-06 ICN-UNAM-06/05G

3. Departamento de Física de Altas Energías, - Elena Cáceres; Alberto Güijosa; Bernal Díaz Del Castillo
ABSTRACT: Following recent developments, we employ the AdS/CFT correspondence to determine the drag force exerted on an external quark that moves through an N = 4 super-Yang-Mills plasma with a non-zero R-charge density (or, equivalently, a non-zero chemical potential). We find that the drag force is larger than in the case where the plasma is neutral. UTTG-07-06 ICN-UNAM-06/05G

4. ¶Departamento de Física de Altas Energías - Facultad De Física; Católica Chile; Autónoma México
Abstract. We provide a method and the results for the calculation of the holonomy of a Yang-Mills connection in an arbitrary triangular path, in an expansion (developed here to fifth order) in powers of the corresponding segments. The results might have applications in generalizing to Yang-Mills fields previous calculations of the corrections to particle dynamics induced by loop quantum gravity, as well as in the field of random lattices. PACS numbers: 04.60.Pp, 11.55.Fv, 12.38.Gc

5. Departamento de Física de Altas Energías, - Strongly-coupled Plasmas; Elena Cáceres; Alberto Güijosa; Bernal Díaz Del Castillo; Apdo Postal; México D. F
ABSTRACT: We compute the drag force experienced by a heavy quark that moves through plasma in a gauge theory whose dual description involves arbitrary metric and dilaton fields. As a concrete application, we consider the cascading gauge theory at temperatures high above the deconfining scale, where we obtain a drag force with a non-trivial velocity dependence. We compare our results with the jet-quenching parameter for the same theory, and find qualitative agreement between the two approaches. Conversely, we calculate the jetquenching parameter for N = 4 super-Yang-Mills with an R-charge density (or equivalently, a chemical potential), and compare our result...

6. ¶Departamento de Física de Altas Energías - Católica Chile; Autónoma México
Abstract. We provide a method and the results for the calculation of the holonomy of a Yang-Mills connection in an arbitrary triangular path, in an expansion (developed here to fifth order) in powers of the corresponding segments. The results might have applications in generalizing to Yang-Mills fields previous calculations of the corrections to particle dynamics induced by loop quantum gravity, as well as in the field of random lattices. PACS numbers: 04.60.Pp, 11.55.Fv, 12.38.Gc

7. d - Jorge Alfaro A; Hugo A. Morales-técotl Bc; Luis F. Urrutia D; Facultad De Física; Católica Chile; Metropolitana Iztapalapa; Altas Energías
Quantum gravity phenomenology opens up the possibility of probing Planck scale physics. Thus, by exploiting the generic properties that a semiclassical state of the compound system fermions plus gravity should have, an effective dynamics of spin-1/2 particles is obtained within the framework of loop quantum gravity. Namely, at length scales much larger than Planck length ℓP ∼ 10 −33 cm and below the wave length of the fermion, the spin-1/2 dynamics in flat spacetime includes Planck scale corrections. In particular we obtain modified dispersion relations in vacuo for fermions. These corrections yield a time of arrival delay of the spin...

8. Centro Brasileiro de Pesquisas Fisicas (CBPF) Coordenação de Física Experimental de Altas Energias (LAFEX) - Marcelo Botta Cantcheff; Rua Dr; Xavier Sigaud
We propose a modification of standard linear electrodynamics in four dimensions, where effective non-trivial interactions of the electromagnetic field with itself and with matter fields induce Lorentz violating Chern-Simons terms. This yields two consequences: it provides a more realistic and general scenario for the breakdown of Lorentz symmetry in electromagnetism and it may explain the effective behavior of the electromagnetic field in certain planar phenomena (for instance, Hall effect). A number of proposals for non-linear electrodynamics is discussed along the paper. Important physical implications of the breaking of Lorentz symmetry, such as optical birefringence and the possibility of having conductance...

9. Departamento de Física de Altas Energías, - Strongly-coupled Plasmas; Elena Cáceres; Alberto Güijosa; Bernal Díaz Del Castillo; Apdo Postal; México D. F
ABSTRACT: We compute the drag force experienced by a heavy quark that moves through plasma in a gauge theory whose dual description involves arbitrary metric and dilaton fields. As a concrete application, we consider the cascading gauge theory at temperatures high above the deconfining scale, where we obtain a drag force with a non-trivial velocity dependence. We compare our results with the jet-quenching parameter for the same theory, and find qualitative agreement between the two approaches. Conversely, we calculate the jetquenching parameter for N = 4 super-Yang-Mills with an R-charge density (or equivalently, a chemical potential), and compare our result...

10. Departamento de Física de Altas Energías, - J. Antonio García; Román Linares; J. David Vergara; A. Postal; México D. F
Conformal invariant new forms of p-brane and Dp-brane actions are proposed. These are quadratic in ∂X for the p-brane case and for Dp-branes in the Abelian field strength. The fields content of these actions are: an induced metric, gauge fields, an auxiliary metric and an auxiliary scalar field. The proposed actions are Weyl invariant in any dimension and the elimination of the auxiliary metric and the scalar field reproduces the Nambu-Goto action for p-branes and the Born-Infeld action for Dp-branes. Comments on symmetry properties of these actions and the construction of their respective Weyl invariant energy-momentum tensor are worked out....

11. Departamento de Física de Altas Energías, - J. Antonio García; Román Linares; J. David Vergara; A. Postal; México D. F
Conformal invariant new forms of p-brane and Dp-brane actions are proposed. The field content of these actions are: an induced metric, gauge fields, an auxiliary metric and an auxiliary scalar field that implements the Weyl invariance. This scalar field transforms with a conformal weight that depends on the brane dimension. The proposed actions are Weyl invariant in any dimension and the elimination of the auxiliary metric and the scalar field reproduces the Nambu-Goto action for p-branes and the Born-Infeld action for Dp-branes. As a consequence of the fact that in the p-brane case, the action is quadratic in ∂0X, we...

12. Departamento de Física de Altas Energías, - J. Antonio García; Román Linares; J. David Vergara; A. Postal; México D. F
Conformal invariant new forms of p-brane and Dp-brane actions are proposed. The field content of these actions are: an induced metric, gauge fields, an auxiliary metric and an auxiliary scalar field that implements the Weyl invariance. This scalar field transforms with a conformal weight that depends on the brane dimension. The proposed actions are Weyl invariant in any dimension and the elimination of the auxiliary metric and the scalar field reproduces the Nambu-Goto action for p-branes and the Born-Infeld action for Dp-branes. As a consequence of the fact that in the p-brane case, the action is quadratic in ∂0X, we...

13. Departamento de Física Nuclear e Altas Energias - A. Delfino A; M. Malheiro A; L. V. Belvedere A; A. O. Gattone C
The equation of state of saturated nuclear matter is derived using two different derivativecoupling Lagrangians. We show that both descriptions are equivalent and can be obtained from the σ − ω model through an appropriate rescaling of the coupling constants. We introduce generalized forms of this rescaling to study the correlations amongst observables in infinite nuclear matter, in particular, the compressibility and the effective nucleon mass. PACS number(s): 21.65.+f, 21.30.+y, 97.60.Jd 1 1

14. IN THE EFFECTIVE THEORY APPROACH - Faculdade De Ciências; Departamento De Física; Renato Batista; Guedes Júnior; Doutoramento Em Física; Universidade De Lisboa; Faculdade De Ciências; Departamento De Física; Renato Batista; Guedes Júnior; Orientadores Doutor; Rui Alberto; Serra Ribeiro Santos; Doutor Augusto; Manuel Albuquerque Barroso
friendship, I would never have been able to pursue this thesis. I would also like to thank Professor Pedro Miguel Martins Ferreira for the assistance he provided at all levels of the research project. I also thank Professor Orlando Oliveira, Rita Coimbra and Miguel Won for the assistance they provided of the research Project. I must acknowledge Professor António Onofre, Professor Arhrib Abdesslam and Professor Pedro Texeira-Dias for receive me in their research groups and give me all the support. A very special thanks to Steven Warren, Ana Catarina and António Paço to help me in theirs free time in...

15. Characteristics of newly diagnosed women with breast cancer;a comparison with the recommendations of the WCRF/AICR Second Report - Ceccatto, V.; Cesa, C.; Kunradi Vieira, Francilene Gracieli; Altenburg de Assis, Mª A.; Crippa, Carlos Gilberto; Faria Di Pietro, Patricia
Introduccion: El Segundo Informe Pericial, Alimentacion, Nutricion, Actividad Fisica y la prevencion del cancer: una perspectiva global de la Fundacion Mundial para la Investigacion del Cancer del Instituto Americano para la Investigacion del Cancer (WCRF / AICR), incluye recomendaciones generales y especiales para la prevencion del cancer. Objetivo: Evaluar las caracteristicas nutricionales y del estilo de vida de las mujeres con diagnostico reciente de cancer de mama segun el recomendaciones del Segundo Informe de la WCRF/AICR. Metodos: Este estudio transversal se realizo en una muestra de 133 mujeres. Los datos de la dieta se obtuvieron mediante cuestionario de frecuencia de alimentos y los datos antropometricos mediante procedimientos estandar. Las caracteristicas de la poblacion de estudio fueron...

16. Cazando lo invisible: una mirada antropológica en el laboratorio - Santamarina Campos, Beatriz
Este cuaderno presenta algunos resultados del trabajo de campo realizado en el CERN, Laboratorio Europeo de Física de Partículas, y en el Departamento de Física Nuclear de la Universidad de Ginebra dentro de un experimento, el AMS (Alpha Magnetic Spectrometer) que tiene como objetivo último instalar en el 2007 un espectrómetro en la ISS (Estación Espacial Internacional) para estudiar los rayos cósmicos. En la primera parte de mi exposición me centraré en presentar cómo se realizó el trabajo de campo, qué técnicas se utilizaron y porqué se escogieron. En la segunda, expondré los preparativos y la realización de un test beam cuya finalidad era comprobar parte de los detectores que...

17. Física de astropartículas de alta energía - Tueros, Matías Jorge
Los rayos cósmicos de energía extrema son partículas subatómicas que llegan a la tierra con energías mayores a 10¹⁸ eV. Su flujo es muy reducido (menos de 1 rayo cósmico primario por kilómetro cuadrado y por siglo) y sólo pueden ser detectados a través de las cascadas de partículas que producen tras el impacto con un núcleo de la atmósfera. La determinación del origen, la composición y el espectro energético de los rayos cósmicos de energía extrema representa uno de los mayores retos para la física de astropartículas en la actualidad. Hace ya más de 15 años un grupo de científicos...

18. El Principio de Equivalencia, su verificación experimental y su relación con las fuerzas fundamentales - Riveros, Ricardo Carlos
La exploración experimental del Principio de Equivalencia y de la "correcta" teoría de la gravitación tiene importantes consecuencias para la física actual. Esta exploración se basa en la proposición de nuevos y mas precisos experimentos, en el análisis y reanálisis de experimentos ya realizados desde nuevos puntos de vista y en la formulación de modelos teóricos adecuados tanto como hipótesis de trabajo para la comprensión del fenómeno gravitatorio en sí o como base para proponer experimentos e interpretar su resultado. En este trabajo, se intenta cubrir algunos de estos aspectos, ya que: a) Se reanaliza un experimento realizado para comprobar...

19. Radiación no-térmica asociada a ondas de choque astrofísicas - Araudo, Anabella T.
El objetivo principal de esta tesis es investigar los procesos físicos que dan lugar a emisión no-térmica a altas energías en objetos astrofísicos capaces de acelerar partículas hasta velocidades relativistas. En particular, se ha estudiado la emisión de rayos gamma producida en fuentes cósmicas con diferentes escalas espaciales, desde objetos estelares jóvenes hasta cúmulos de galaxias, pasando por microcuasares y núcleos de galaxias activas. En los dos primeros tipos de objetos se ha modelado la emisión de rayos gamma a partir de los datos obtenidos en frecuencias radio de las fuentes IRAS 16547-4247 y Abell 3376. En los dos últimos,...

20. El proyecto MINERvA y la Universidad de Guanajuato - Félix, J.; Urrutia, Z.; Castonera, J.; Higuera, A.; Gutiérrez, R.; Zavala, G.
La física de altas energías experimental es relativamente nueva en México, no tiene más de 20 años. El grupo de física experimental del Instituto de Física de la Universidad de Guanajuato (IFUG) (ahora División de Ciencias e Ingenierías, Campus León) es pionero en esta área de la física en México. Este grupo inició actividades en 1989, aproximadamente, con la colaboración Brookhaven National Laboratory BNL e766. Esta colaboración continuó con el experimento Fermi Nacional Accelerator Laboratory (FNAL e690), después con el FNAL e871, y actualmente con el FNAL e938, MINERvA (Main INjector ExpeRiment for v -A). En las colaboraciones BNL e766,...

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