123472999
Finite Symmetry Transformation Groups and Exact Solutions of Three Generalized Breaking Soliton Equations
We investigate Bogoyavlenskii's generalized breaking soliton equations and their extension form with the modified direct Clarkson-Kruskal (CK) method. Then, we get the Lie point groups and the full symmetry group, and a relationship is constructed between the new solutions and the old one. Based on the relationship, the new solutions can be obtained by using a given solution of the equations.
119414675
(3 + 1)-dimensional models with an infinitely dimensional Virasoro type symmetry algebra
Abstract Using every realization of the centerless Virasoro type symmetry algebra, [σ(f 1 (t)), σ(f 2 (t))] = σ( f 1 f 2 − f 2 f 1 ) , we obtain various higher dimensional models. By means of a concrete realization, many (3 + 1)-dimensional equations which possess a Kac-Moody-Virasoro type infinite dimensional symmetry algebra are obtained.
121838816
Supersymmetric Ito equation: Bosonization and exact solutions
Based on the bosonization approach, the N=1 supersymmetric Ito (sIto) system is changed to a system of coupled bosonic equations. The approach can effectively avoid difficulties caused by intractable fermionic fields which are anticommuting. By solving the coupled bosonic equations, the traveling wave solutions of the sIto system are obtained with the mapping and deformation method. Some novel types of exact solutions for the supersymmetric system are constructed with the solutions and symmetries of the usual Ito equation. In the meanwhile, the similarity reduction solutions of the model are also studied with the Lie point symmetry theory.
115316129
Long distance contribution to the KL-KS mass difference
We develop and demonstrate techniques needed to compute the long distance contribution to the ${K}_{L}\ensuremath{-}{K}_{S}$ mass difference, $\ensuremath{\Delta}{M}_{K}$, in lattice QCD and carry out a first, exploratory calculation of this fundamental quantity. The calculation is performed on $2+1$ flavor, domain wall fermion, ${16}^{3}\ifmmode\times\else\texttimes\fi{}32$ configurations with a 421 MeV pion mass and an inverse lattice spacing $1/a=1.73\text{ }\text{ }\mathrm{GeV}$. We include only current-current operators and drop all disconnected and double penguin diagrams. The short distance part of the mass difference in a $2+1$ flavor calculation contains a quadratic divergence cut off by the lattice spacing. Here, this quadratic divergence is eliminated through the Glashow-Iliopoulos-Maiani mechanism by introducing a valence charm quark. The inclusion of the charm quark makes the complete calculation accessible to lattice methods provided the discretization errors associated with the charm quark can be controlled. The long distance effects are discussed for each parity channel separately. While we can see a clear signal in the parity odd channel, the signal to noise ratio in the parity even channel is exponentially decreasing as the separation between the two weak operators increases. We obtain a mass difference $\ensuremath{\Delta}{M}_{K}$ which ranges from $6.58(30)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}12}\text{ }\text{ }\mathrm{MeV}$ to $11.89(81)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}12}\text{ }\text{ }\mathrm{MeV}$ for kaon masses varying from 563 to 839 MeV. Extensions of these methods are proposed which promise accurate results for both $\ensuremath{\Delta}{M}_{K}$ and ${ϵ}_{K}$, including long distance effects.
119181511
Probing Color Octet Couplings at the Large Hadron Collider
Color-octet resonances arise in many well motivated theories beyond the standard model. As colored objects they are produced copiously at the LHC and can be discovered in early searches for new physics in dijet final states. Once they are discovered it will be important to measure the couplings of the new resonances to determine the underlying theoretical structure. We propose a new channel, associated production of $W,Z$ gauge bosons and color-octet resonances, to help determine the chiral structure of the couplings. We present our analysis for a range of color-octet masses (2.5 to 4.5 TeV), couplings and decay widths for the LHC with center of mass energy of 14 TeV and 10 ${\rm fb}^{-1}$ or 100 ${\rm fb}^{-1}$ of integrated luminosity. We find that the LHC can probe a large region of the parameter space up to very small couplings.
124175693
A New Approach for Calculating Spin Susceptibility in QED3
Based on the study of the linear response of the fermion propagator to the presence of an external scalar field, a new method for calculating the staggered spin susceptibility in QED3 is presented, in which the influence of the full vertex function is included. The numerical values of the staggered spin susceptibility are calculated within the framework of the rainbow-ladder approximation of the Dyson–Schwinger approach. A comparison between the result calculated using the full vertex and that using the bare vertex is given.
204003920
Mesure de la section efficace de production de paires de quarks, top-antitop à l’aide des premières données du détecteur ATLAS auprès du LHC
Le but de la these est de mesurer la section efficace de production de quarks top-antitop dans le canal lepton + jets dans l'experience ATLAS au Grand collisionneur de hadrons (LHC). L'analyse utilise les donnees des collisions proton-proton a 7 TeV collectees en 2010 avec une luminosite integree de 33,7 pb-1. La selection des evenements est basee sur la signature de la topologie top-antitop avec 1 electron ou muon, une grande energie transverse manquante et au moins 4 jets. Le fond QCD multijets est mesure avec les donnees elles-memes par une "Methode Matricielle". Trois methodes sont utilisees pour mesurer le fond W+jets, la methode d’asymetrie de charge, la methode de Berends-Giele et une methode combinant les deux precedentes. Les autres bruits de fond sont estimes a partir MC. Le nombre d'evenements de signal top-antitop est obtenu en ajustant la distribution du nombre de jets etiquetes b, en mesurant simultanement l'efficacite d‘etiquetage des quarks b. La section efficace top-antitop est mesuree a 148,1±34,9 pb. Elle est compatible avec la prediction du Modele Standard a l’ordre NNLO calculee par le logiciel Hathor. Elle est egalement en accord avec les mesures par d'autres methodes. Avec plus de donnees sur les collisions en 2011, on peut s'attendre a une mesure plus precise de la section efficace top-antitop.
124149505
Wigner solution to the quark gap equation in the nonzero current quark mass
From the graphical representation of the Dyson—Schwinger equation for the dressed gluon propagator it is shown that the gluon propagator in the Wigner phase should be different from that in the Nambu phase. Based on this analysis, we propose a modified gluon propagator to reflect this fact. With such a modified gluon propagator, in the framework of the Nambu—Jona—Lasinio (NJL) model, we obtain the Wigner solution to the quark gap equation at finite current quark mass, which has not been found in literature. This provides a new point of view to study partial restoration of chiral symmetry at finite temperature and chemical potential.