The Minimal Moose for a Little Higgs

Recently a new class of theories of electroweak symmetry breaking have been constructed. These models, based on deconstruction and the physics of theory space, provide the first alternative to weak-scale supersymmetry with naturally light Higgs fields and perturbative new physics at the TeV scale. The Higgs is light because it is a pseudo-Goldstone boson, and the quadratically divergent contributions to the Higgs mass are cancelled by new TeV scale ``partners'' of the {\em same} statistics. In this paper we present the minimal theory space model of electroweak symmetry breaking, with two sites and four link fields, and the minimal set of fermions. There are very few parameters and degrees of freedom beyond the Standard Model. Below a TeV, we have the Standard Model with two light Higgs doublets, and an additional complex scalar weak triplet and singlet. At the TeV scale, the new particles that cancel the 1-loop quadratic divergences in the Higgs mass are revealed. The entire Higgs potential needed for electroweak symmetry breaking--the quartic couplings as well as the familiar negative mass squared--can be generated by the top Yukawa coupling, providing a novel link between the physics of flavor and electroweak symmetry breaking.Comment: 15 pages. References added. Included clarifying comments on the origin of quartic couplings, and on power-counting. More elegant model for generating Higgs potential from top Yukawa coupling presente

On the one-loop Kahler potential in five-dimensional brane-world supergravity

We present an on-shell formulation of 5d gauged supergravity coupled to chiral matter multiplets localized at the orbifold fixed points. The brane action is constructed via the Noether method. In such set-up we compute one-loop corrections to the Kahler potential of the effective 4d supergravity and compare the result with previous computations based on the off-shell formalism. The results agree at lowest order in brane sources, however at higher order there are differences. We explain this discrepancy by an ambiguity in resolving singularities associated with the presence of infinitely thin branes.Comment: 20 page

Beyond Mean Field Confrontation of Different Models with High Transverse Momentum Proton Spectra

Several models have been proposed to simulate heavy ion reactions beyond the mean field level. The lack of data in phase space regions which may be sensitive to different treatments of fluctuations made it difficult to judge these approaches. The recently published high energy proton spectra, measured in the reaction 94 AMeV Ar + Ta, allow for the first time for a comparison of the models with data. We find that these spectra are reproduced by Quantum Molecular Dynamics (QMD) and Boltzmann Uehling Uhlenbeck (BUU) calculations. Models like Boltzmann Langevin (BL) in which additional fluctuations in momentum space are introduced overpredict the proton yield at very high energies. The BL approach has been successfully used to describe the recently measured very subthreshold kaon production assuming that the fluctuations provide the necessary energy to overcome the threshold in two body collisions. Our new findings suggest that the very subthreshold kaon production cannot be due to two body scattering and thus remains a open problem.Comment: 5 pages, 3 figures (eps), revte

Dilaton constraints and LHC prospects

The Standard Model Higgs searches using the first 1-2 fb-1 of LHC data can be used to put interesting constraints on new scalar particles other than the Higgs. We investigate one such scenario in which electroweak symmetry is broken via strongly coupled conformal dynamics. This scenario contains a neutral scalar dilaton---the Goldstone boson associated with spontaneously broken scale invariance---with a mass below the conformal symmetry breaking scale and couplings to Standard Model particles similar (but not identical) to those of the Standard Model Higgs boson. We translate the LEP and LHC Higgs limits to constrain the dilaton mass and conformal breaking scale. The conformal breaking scale f is constrained to be above 1 TeV for dilaton masses between 145 and 600 GeV, though it can be as low as 400 GeV for dilaton masses below 110 GeV. We also show that (i) a dilaton chi with mass below 110 GeV and consistent with the LEP constraints can appear in gg --> chi --> gamma gamma with a rate up to ~10 times the corresponding Standard Model Higgs rate, and (ii) a dilaton with mass of several hundred GeV is much narrower than the corresponding Standard Model Higgs, leading to improved search sensitivity in chi --> ZZ --> 4l.Comment: 15 pages, 12 figures, References added, Figure 10 modified, Figure 11 adde

Phenomenology of Electroweak Symmetry Breaking from Theory Space

Recently, a new class of realistic models for electroweak symmetry breaking have been constructed, without supersymmetry. These theories have naturally light Higgs bosons and perturbative new physics at the TeV scale. We describe these models in detail, and show that electroweak symmetry breaking can be triggered by a large top quark Yukawa coupling. A rich spectrum of particles is predicted, with a pair of light Higgs doublets accompanied by new light weak triplet and singlet scalars. The lightest of these new scalars is charged under a geometric discrete symmetry and is therefore stable, providing a new candidate for WIMP dark matter. At TeV energies, a plethora of new heavy scalars, gauge bosons and fermions are revealed, with distinctive quantum numbers and decay modes.Comment: 22 pages, latex, 6 figures. Numerical results corrected, clarifications added, conclusions unchange

Selective Modulators of PPAR-γ Activity: Molecular Aspects Related to Obesity and Side-Effects

Peroxisome proliferator-activated receptor γ (PPAR-γ) is a key regulator of lipid metabolism and energy balance implicated in the development of insulin resistance and obesity. The identification of putative natural and synthetic ligands and activators of PPAR-γ has helped to unravel the molecular basis of its function, including molecular details regarding ligand binding, conformational changes of the receptor, and cofactor binding, leading to the emergence of the concept of selective PPAR-γ modulators (SPPARγMs). SPPARγMs bind in distinct manners to the ligand-binding pocket of PPAR-γ, leading to alternative receptor conformations, differential cofactor recruitment/displacement, differential gene expression, and ultimately differential biological responses. Based on this concept, new and improved antidiabetic agents for the treatment of diabetes are in development. This review summarizes the current knowledge on the mechanism of action and biological effects of recently characterized SPPARγMs, including metaglidasen/halofenate, PA-082, and the angiotensin receptor antagonists, recently characterized as a new class of SPPARγMs

Do ultrafast exciton-polaron decoherence dynamics govern photocarrier generation efficiencies in polymer solar cells?

All-organic-based photovoltaic solar cells have attracted considerable attention because of their low-cost processing and short energy payback time. In such systems the primary dissociation of an optical excitation into a pair of photocarriers has been recently shown to be extremely rapid and efficient, but the physical reason for this remains unclear. Here, two-dimensional photocurrent excitation spectroscopy, a novel non-linear optical spectroscopy, is used to probe the ultrafast coherent decay of photoexcitations into charge-producing states in a polymer:fullerene based solar cell. The two-dimensional photocurrent spectra are interpreted by introducing a theoretical model for the description of the coupling of the electronic states of the system to an external environment and to the applied laser fields. The experimental data show no cross-peaks in the two-dimensional photocurrent spectra, as predicted by the model for coherence times between the exciton and the photocurrent producing states of 20\,fs or less

Rapport au Roi Souverain : rapport de la Commission d'Enquête ; A. M. le Secrétaire d'État de l'État Indépendant du Congo [31 octobre 1905]

Bakgrund: Den palliativa vården för hälso- och sjukvårdspersonal innebär att försöka uppnå den döende personens maximala livskvalitet och att lindra lidandet. Vården lutar sig mot det nationella vårdprogrammet för palliativ vård samt International Council of Nurses, ICN. Sjuksköterskans roll och uppgifter inom vården beskrivs där även de fyra hörnstenarna belyses. Syfte: Att belysa sjuksköterskornas upplevda svårigheter vid vård av patienter med palliativ diagnos. Metod: Examensarbetet är en litteraturöversikt baserad på Fribergs analysmetod. Denna litteraturöversikt inkluderar tio vetenskapliga artiklar som har sökts i databaserna CINAHL Complete och PubMed. Som en teoretisk utgångspunkt har Patricia Benners teori från novis till expert valts som en diskussion i resultatdiskussionen. Resultat: Sjuksköterskornas upplevda svårigheter av att vårda patienter med en palliativ diagnos resulterade i fyra huvudteman i litteraturöversikten; kommunikation, närstående och relation, vårdteamet samt kunskap och erfarenheter. Diskussion: Resultatet i litteraturöversikten har diskuterats utifrån Benners teori. Sjuksköterskornas upplevda svårigheter belystes genom fyra teman – kunskap och erfarenhet, närståendestöd, kommunikation mellan kollegor och gentemot patienten samt kultur som upplevd svårighet.Background: Palliative care for health professional means trying to achieve the maximum dying person's quality of life and ease suffering. The palliative care for health professionals means to try to achieve the dying person's maximum quality of life and alleviate suffering. The care inclined towards the Swedish national health care program for palliative care and the International Council of Nurses, ICN. The nurse's role and tasks in health care are described where even the four cornerstones elucidated. Aim: To elucidate the nurses perceived difficulties in nursing patients with palliative diagnosis. Method: The thesis is a literature review based on Friberg's analysis. This literature review includes ten scientific articles that have been searched in the databases CINAHL Complete and PubMed. As a theoretical base, Patricia Benner's theory from novice to expert was selected as a discussion of the results discussion. Results: The nurses perceived difficulties of caring for patients with a palliative diagnosis resulted in four main themes in the literature; communication, family and relationship, the health care team as well as knowledge and experience. Discussion: The results of the literature review are discussed based on Benner's theory. The nurses' perceived difficulties irradiated by four themes – knowledge and experience, family support, communication between colleagues and towards the patient as well the culture as perceived difficulties