Two Composite Higgs Doublets: Is it the Low Energy Limit of a Natural Strong Electroweak Symmetry Breaking Sector ?

In this paper, we construct an effective model that describes the electroweak symmetry breaking sector by means of composite Higgs-like scalars, following the ideas of Minimal Walking Technicolor (MWT). We argue that, because of the general failure of Extended Technicolor (ETC) to explain the mass of the top quark, it is necessary to introduce two composite Higgs bosons: one of them originated by a MWT-ETC sector and the other one produced by a Topcolor sector. We focus on the phenomenological differences between the light composite Higgs present in our model and the fundamental Higgs boson predicted by the Standard Model and their production at the LHC. We show that in this scheme the main production channel of the lighter Higgs boson are the associated production with a gauge boson and $WW$ fusion but not the gluon-gluon fusion channel which is substantially suppressed.Comment: Version accepted in Modern Physics Letters

Constraining Spin-One Color-Octet Resonances Using CDF and ATLAS Data

In this paper, we study the production of spin-one color-octet resonances (colorons) at hadron colliders in a model independent way. We use dijets data measured by CDF (at \sqrt{s}=1.96 TeV and L=1.13$1/pb) and ATLAS (at \sqrt{s}=7$ TeV and L=315 1/nb) collaborations at the Tevatron and the LHC respetively to impose limits on the coupling of colorons to fermions. We show that CDF data still produce the more stringent limits on the coloron coupling constant.Comment: Version accepted for publication in EPJC. Two paragraphs expanded and new references adde

Associate Higgs and Gauge Boson Production at Hadron Colliders in a Model with Vector Resonances

Motivated by new models of dynamical electroweak symmetry breaking that predict a light composite higgs boson, we build an effective lagrangian which describes the Standard Model (with a light Higgs) and vector resonances. We compute the cross section for the associate production of a higgs and a gauge boson. For some values of model parameters we find that the cross section is significantly enhanced with respect to the Standard Model. This enhancement is similar at the LHC and the Tevatron for the same range of resonance mass

Axigluon Phenomenology using ATLAS dijet data

In recent years, there has been a renewed interest on axigluons as part of a possible extension of strong interactions at high energies. In this work, we use recent ATLAS measurements of the dijet spectrum in order to set limits on the axigluon mass and coupling to quarks. We pay special attention to the methodology used to extract the resonant contribution from theoretical simulations. Finally, we present some predictions for the next LHC run at $\sqrt{s}=14$ TeV

Ultrasonic transducer with Gaussian radial pressure distribution

An ultrasonic transducer that produces an output that is a symmetrical function comprises a piezoelectric crystal with several concentric ring electrodes on one side of the crystal. A resistor network applies different amplitudes of an ac source to each of the several electrodes. A plot of the different amplitudes from the outermost electrode to the innermost electrode is the first half of a Gaussian function. Consequently, the output of the crystal from the side opposite the electrodes has a Gaussian profile