Nowadays two important frontiers in the physical world remain as an intellectual challenge: the extremely small and the extremely large domains. The TeV regime that will be reached at the Large Hadron Collider will allow the investigation of distances of 10^-19 m. On the other hand, the cosmological scale can also give important contribution to our understanding of Nature since it provides a unique view of the formation of the universe and the behavior of matter under extreme conditions.

       The investigation of the fundamental interactions and the interplay between these two scales is the main purpose of our project. The group is devoted to the analyses of several aspects of some pressing questions like the study the gravitational interaction and its cosmological implications, the development of new models and tools to describe Nature, to establish a bridge between the new theoretical ideas and experimental results, and to conduct experiments in high energy colliders.

       We are creating a Virtual Institute devoted to the study of the fundamental interactions. This will allow our group to participate in a stimulating environment where theoretical and experimental ideas come together to lead to a better understanding of the universe. We intend to maintain a vigorous experimental program in High Energy Physics, in close contact with the theory group.

       The cornerstone of our project is the construction of a PC farm which will be used both by experimentalists and theorists. Furthermore, this farm will be integrated with the system being planned to perform the data analysis of the Large Hadron Collider experiments. This system introduces a new concept in computing since the available computing power in many sites throughout the world will be shared by the community. Certainly this new concept will have far reaching consequences as the previous introduction of the world wide web by the high energy community in the past.

  Experimental High Energy Physics

       The group started a Experimental High Energy program at Fermilab in 1983. The group from Lafex participated in the experiments of charm photoproduction (E691), and charm hadroproduction (E769). The group played a very important role in the Advanced Computing Projet responsible for the construction of the hardware for parallel processing. In 1989 we joined the DØ Collaboration and contributed to the muon detector electronics and to the analysis of bottom quark production. Some of the members of our group have contributed to the data analysis of the Delphi Collaboration at CERN.

       Nowadays we are involved in the project of the Forward Proton Detector (FPD) of DØ. The FPD consists of a series of detectors that were installed close to the beam line of the Fermilab Tevatron, complementing and improving the present DØ detector. They increased the reach of the DØ cedntral detector in the search for a new class of phenomena still unknown: the high energy hadronic diffraction.

       The future plans of the group include an active participation in the CMS Collaboration of the Large Hadron Collider at CERN. For this purpose its is essencial to have access to new data through the The Particle Physics Data Grid

  Particle Physics Phenomenology

      The Glashow-Weinberg-Salam model (standard model, SM) for the electroweak interactions describes successfully all the presently available experimental information. During the last decades it was established the existence of three generations of fermions in agreement with the SM structure. We have also produced and studied in detail the weak vector bosons, validating the SM at the quantum level. Moreover, new signals for CP violation have been observed in neutral B systems in addition to well known ones in the K⁰ system. The three neutrinos have been directly observed and compelling evidence of neutrino flavor oscillation has been gathered. Notwithstanding there are many pressing problems without a satisfactory answer. For instance, little is known about the symmetry breaking sector or the origin of masses and CP violation. In fact this decade will be dedicated to unravel the mechanism of the electroweak symmetry breaking and flavor physics.

       The increase of the available center-of-mass energy of present and future accelerators leads to a very large production of particles. Therefore, the data analysis becomes much more involved requiring in many cases theoretical guidance to interpret and extract signals immersed in a large background. With the turn-on of the Large Hadron Collider (LHC) in 2005, collider physics phenomenology will become the central area of particle theory. The LHC is the first machine to reach the required energies to systematically investigate electroweak symmetry breaking, to probe supersymmetry at the mass scales where superpartners are most likely to be found, or to open the door to the unexpected, like the conjectured existence of extra dimensions.

       The hallmark of the particle phenomenology effort is the close interaction with experimental groups, bridging the gap between theory and experiment and offering help on the possible signal of new physics. Researchers in our phenomenology group pursue a broad range of interests in particle physics theory and phenomenology. This includes neutrino physics, strong interaction dynamics, and collider physics, specially the search for the Higgs boson, supersymmetric and other new particles.

  Field Theory