Addition theorems and the Drach superintegrable systems

We propose new construction of the polynomial integrals of motion related to the addition theorems. As an example we reconstruct Drach systems and get some new two-dimensional superintegrable Stackel systems with third, fifth and seventh order integrals of motion.Comment: 18 pages, the talk given on the conference "Superintegrable Systems in Classical and Quantum Mechanics", Prague 200

Rho meson decay width in SU(2) gauge theories with 2 fundamental flavours

7 pages, Proceedings of the 34th International Symposium on Lattice Field Theory (Lattice 2016)SU(2) gauge theories with two quark flavours in the fundamental representation are among the most promising theories of composite dynamics describing the electroweak sector. Three out of five Goldstone bosons in these models become the longitudinal components of the W and Z bosons giving them mass. Like in QCD, we expect a spectrum of excitations which appear as resonances in vector boson scattering, in particular the vector resonance corresponding to the rho-meson in QCD. In this talk I will present the preliminary results of the first calculation of the rho-meson decay width in this theory, which is analogous to rho to two pions decay calculation in QCD. The results presented were calculated in a moving frame with total momentum (0,0,1) on two ensembles. Future plans include using 3 moving frames on a larger set of ensembles to extract the resonance parameters more reliably and also take the chiral and continuum limits

Composite electroweak sectors on the lattice

In the post-Higgs discovery era, the primary goal of the Large Hadron collider is to discover new physics Beyond the Standard Model. One fundamental question is does new beyond the Standard Model composite dynamics provides the origin of the Higgs field and potential. After reviewing the main motivations to consider composite models based on a new strongly interacting sector, we summarise the efforts of the lattice community to investigate the viability of models featuring a composite Higgs sector. We argue that first principle calculations are necessary in view of the fast improvements in accuracy of experimental measurements in the Higgs sector. We stress the importance for lattice calculations to provide a testing benchmark for non perturbative mechanisms. It is highlighted that the rich phenomenology of non-abelian gauge theories raises a number of questions that can be explored using lattice calculations. First principle results therefore provide crucial insights in the theory landscape that could guide the next generation of Composite Higgs models.Comment: Proceedings of 37th International Symposium on Lattice Field Theory - Lattice201

From strange to charmed baryons using two-flavour QCD

International audienc

Nambu-Jona-Lasinio model with Wilson fermions

12 pages, 5 figuresWe present a lattice study of a Nambu Jona-Lasinio (NJL) model using Wilson fermions. Four fermion interactions are a natural part of several extensions of the Standard Model, appearing as a low energy description of a more fundamental theory. In models of dynamical electroweak symmetry breaking they are used to endow the Standard Model fermions with masses. In infrared conformal models these interaction, when sufficiently strong, can alter the dynamics of the fixed point, turning the theory into a (near) conformal model with desirable features for model building. As a first step toward the nonperturbative study of these models, we study the phase space of the ungauged NJL model

On the Drach superintegrable systems

Cubic invariants for two-dimensional degenerate Hamiltonian systems are considered by using variables of separation of the associated St\"ackel problems with quadratic integrals of motion. For the superintegrable St\"ackel systems the cubic invariant is shown to admit new algebro-geometric representation that is far more elementary than the all the known representations in physical variables. A complete list of all known systems on the plane which admit a cubic invariant is discussed.Comment: 16 pages, Latex2e+Amssym

Оптимизация параметров шумоподавления фильтров высокопроизводительных источников питания

For a noise-reduction filter, the parameters of the manufactured device often do not fit the expected parameters during development, what is caused by the spread of the parameters of the electronic components or their parasitic parameters, as well as due to the presence of its own capacitance and inductance of the frequency response assembly. In this article, the influence of parasitic parameters of components and fasteners on the filter frequency response is considered. Utilizing the electronic simulator software, the filter parameters were modeled in the frequency range from 10 kHz to 1 GHz. Based on the simulation results, recommendations were given for optimizing the filter mounting elements and changing the inductance of low-frequency chokes

Wilson Fermions with Four Fermion Interactions

Contribution to proceedings of the 33rd International Symposium on Lattice Field Theory (Lattice 2015), 14-18 July 2015, Kobe, JapanWe present a lattice study of a four fermion theory, known as Nambu Jona-Lasinio (NJL) theory, via Wilson fermions. Four fermion interactions naturally occur in several extensions of the Standard Model as a low energy parameterisation of a more fundamental theory. In models of dynamical electroweak symmetry breaking these operators, at an effective level, are used to endow the Standard Model fermions with masses. Furthermore these operators, when sufficiently strong, can drastically modify the fundamental composite dynamics by, for example, turning a strongly coupled infrared conformal theory into a (near) conformal one with desirable features for model building. As first step, we study spontaneous chiral symmetry breaking for the lattice version of the NJL model

Template Composite Dark Matter : SU(2) gauge theory with 2 fundamental flavours

Contribution to proceedings of the 33rd International Symposium on Lattice Field Theory (Lattice 2015), 14-18 July 2015, Kobe, JapanWe present a non perturbative study of SU(2) gauge theory with two fundamental Dirac flavours. We discuss how the model can be used as a template for composite Dark Matter (DM). We estimate one particular interaction of the DM candidate with the Standard Model : the interaction through photon exchange computing the electric polarizability of the DM candidate. Finally, we briefly discuss the viability of the model given the present experimental constraints