New Physics and novel Higgs signals

We review some of the results of our recent work dealing with the novel type of Higgs signals that arise when one considers extensions of the standard model. We discuss first possible deviations on the Higgs couplings due to heavy particles, in the context of the MSSM and with large extra-dimensions. Then, we present several models where it is possible to induce flavor violating Higgs couplings, and probe them at future hadron colliders through the LFV Higgs decay h-> tau mu or with rare top decays.Comment: Talk given at the X Mexican School of Particles and Fields, Playa del Carmen, Mexico, 200

Top-Quark FCNC Decay t->cgg in Topcolor-assisted Technicolor Model

The topcolor-assisted technicolor (TC2) model predicts several pseudo-scalars called top-pions and at loop level they can induce the FCNC top quark decay t->cgg which is extremely suppressed in the Standard Model (SM). We find that in the allowed parameter space the TC2 model can greatly enhance such a FCNC decay and push the branching ratio up to 10^{-3}, which is much larger than the predictions in the SM (10^{-9}) and in the minimal supersymmetric model (10^{-4}). We also compare the result with the two-body FCNC decay t-> cg and find that the branching ratio of t-> cgg is slightly larger than t-> cg. Such enhanced FCNC top quark decays may serve as a good probe of TC2 model at the future top quark factory.Comment: 11 pages, 4 figure

A new method to find the potential center of N-body systems

We present a new and fast method to nd the potential center of an N-body distribution. The method uses an iterative algorithm which exploits the fact that the gradient of the potential is null at its center: it uses a smoothing radius to avoid getting trapped in secondary minima. We have tested this method on several random realizations of King models (in which the numerical computation of this center is rather dicult, due to the constant density within their cores), and com- pared its performance and accuracy against a more straightforward, but computer intensive method, based on cartesian meshes of increasing spatial resolution. In all cases, both methods converged to the same center, within the mesh resolution, but the new method is two orders of magnitude faster. We have also tested the method with one astronomical problem: the evolu- tion of a 105 particle King model orbiting around a xed potential that represents our Galaxy. We used a spherical harmonics expansion N-body code, in which the potential center determination is crucial for the correct force computation. We compared this simulation with another one in which a method previously used to determine the expansion center is employed (White 1983). Our routine gives better results in energy conservation and mass loss.Fil: Aguilar, L. A.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Cruz, F.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Carpintero, Daniel Diego. Universidad Nacional de la Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentin

A Rotating Charged Black Hole Solution in f(R) Gravity

In the context of f(R) theories of gravity, we address the problem of finding a rotating charged black hole solution in the case of constant curvature. The new metric is obtained by solving the field equations and we show that the behavior of it is typical of a rotating charged source. In addition, we analyze the thermodynamics of the new black hole. The results ensures that the thermodynamical properties in f(R) gravities are qualitatively similar to those of standard General Relativity.Comment: 9 pages, no figure

Young Brown Dwarfs as Giant Exoplanet Analogs

Young brown dwarfs and directly-imaged exoplanets have enticingly similar photometric and spectroscopic characteristics, indicating that their cool, low gravity atmospheres should be studied in concert. Similarities between the peculiar shaped H band, near and mid-IR photometry as well as location on color magnitude diagrams provide important clues about how to extract physical properties of planets from current brown dwarf observations. In this proceeding we discuss systems newly assigned to 10-150 Myr nearby moving groups, highlight the diversity of this uniform age-calibrated brown dwarf sample, and reflect on their implication for understanding current and future planetary data.Comment: 5 pages, 3 figures. Proceedings for the conference "Brown dwarfs come of age", 2013 May 20-24, to be published in Memorie della Societa Astronomica Italian