Chern-Simons Correlations on (2+1)D Lattice

We have computed the contribution of zero modes to the value of the number of particles in the model of discrete (2+1)-dimensional nonlinear Schr\"odinger equation. It is shown for the first time that in the region of small values of the Chern-Simons coefficient k there exists a universal attraction between field configurations. For k=2 this phenomenon may be a dynamic origin of the semion pairing in high temperature superconducting state of planar systems.Comment: 9 pages, 2 figures Sabj-class: Strongly Correlated Electron

Saturable discrete vector solitons in one-dimensional photonic lattices

Localized vectorial modes, with equal frequencies and mutually orthogonal polarizations, are investigated both analytically and experimentally in a one-dimensional photonic lattice with saturable nonlinearity. It is shown that these modes may span over many lattice elements and that energy transfer among the two components is both phase and intensity dependent. The transverse electrically polarized mode exhibits a single-hump structure and spreads in cascades in saturation, while the transverse magnetically polarized mode exhibits splitting into a two-hump structure. Experimentally such discrete vector solitons are observed in lithium niobate lattices for both coherent and mutually incoherent excitations.Comment: 4 pages, 5 figures (reduced for arXiv

Energy Bounds of Linked Vortex States

Energy bounds of knotted and linked vortex states in a charged two-component system are considered. It is shown that a set of local minima of free energy contains new classes of universality. When the mutual linking number of vector order parameter vortex lines is less than the Hopf invariant, these states have lower-lying energies.Comment: 4 pages, Latex2

Возможности современных методов лучевой диагностики в определении и предоперационном планировании коарктации аорты у детей до года и младшей возрастной группы

Objective. Evaluation of diagnostic value of modern imaging modalities: trans-thoracic echocardiography (TTE), CT-angiography (CTA) and cardio-MRI in diagnosis and preoperative planning of aortic coarctation correction (CoA) in in infants and young age group children.Materials and methods. 101 pediatric patients (aged 0 to 5 years) with CoA underwent TTE, 98 of them underwent CT, 30 – cardio MRI. On TTE, CTA and cardio-MRI aorta morphometry was performed. The most common anomalies associated with CoA (ventricular septal defect (VSD), patent ductus arteriosus (PDA), aberrant right subclavian artery (ARSA), hypoplastic arch and brachiocephalic vessels anomalies) were assessed.Results. The overall diagnostic accuracy of TTE, CT and cardiac-MRI in diagnosis of CoA were 89.1%, 95.9%, 86.7% respectively. There was no significant difference in the accuracy in detecting CoA between TTE, CT and MRI (p > 0.05). The accuracy of TTE in determining the brachiocephalic vessels anomalies, ARSA and arch hypoplasia was 84%, 93% and 85.3%, respectively. The accuracy of CT in determining the brachiocephalic vessels anomalies, ARSA and arch hypoplasia was 100%, 100% and 98% and cardio-MRI: 97.1%, 98.4% and 96.8%, respectively.Conclusion. TTE is a widely available and safe method, it has a high diagnostic value in determining CoA. Due to limitations in visualization of all parts of the aortic arch and the detection of concomitant anomalies, TTE cannot be the final method in planning the CoA correction. CT and MRI of the heart, as a TTE, are effective methods in the diagnosis of CoA, however, in the assessment of extracardiac anomalies, they equally show a significantly more accurate result.Taking into account the difficulties in conducting MRI of the heart in children under one year and younger age group, the need for a longer stay in anesthesia, the lack of additional diagnostically significant information in comparison with CT of the heart, cardio-MRI is not the method of choice in the primary diagnosis and preoperative planning of correction of CoA in children under one year and younger age group requiring the use of an anesthetic aid for the duration of the scan. Cardio-MRI may be the method of choice in preoperative planning of CoA in small children with absolute contraindications to the radiocontrast agent.Цель исследования: оценить диагностическую эффективность современных методов диагностики: ЭхоКГ, КТ и МРТ сердца в выявлении и хирургическом планировании коррекции коарктации аорты (КоАо) у детей до года и младшей возрастной группы.Материал и методы. В исследование включен 101 ребенок в возрасте от 0 до 5 лет. Всем детям проведено ЭхоКГ, 98 пациентам – КТ сердца, 30 – МРТ сердца. При интерпретации результатов ЭхоКГ, КТ и МРТ сердца осуществлялись анализ и морфометрия всех отделов аорты, проводилась оценка наличия сопутствующих аномалий: аберрантная правая подключичная артерия, септальные дефекты, открытый артериальный проток, патология брахиоцефальных сосудов (БЦС) и сопутствующая гипоплазия дуги аорты.Результаты. Диагностическая точность ЭхоКГ, КТ и МРТ сердца в определении КоАо у детей до года и младшей возрастной группы составили 89,1, 95,9, 86,7% соответственно. В определении патологии БЦС, аберрантной правой подключичной артерии и гипоплазии дуги точность ЭхоКГ составила 84, 93 и 85,3% соответственно. Информативность КТ в определении патологии БЦС, аберрантной правой подключичной артерии и гипоплазии дуги составила 100, 100 и 98% соответственно. Точность кардио-МРТ в определении патологии БЦС, аберрантной правой подключичной артерии и гипоплазии дуги составила 97,1, 98,4 и 96,8% соответственно.Заключение. ЭхоКГ, будучи широкодоступным и безопасным методом, имеет высокую диагностическую ценность в диагностике КоАо, однако ввиду ограничений в визуализации всех отделов дуги аорты и выявления сопутствующих экстракардиальных аномалий не может быть окончательным при планировании коррекции КоАо у маленьких детей. КТ и МРТ сердца наравне с ЭхоКГ являются эффективными методиками в диагностике локального сужения аорты, однако в оценке экстракардиальных аномалий одинаково показывают достоверно более точный результат.Проведение МРТ сердца у детей до года и младшей возрастной группы сопряжено с техническими сложностями и необходимостью более длительного пребывания в наркозе. Учитывая отсутствие дополнительной диагностически значимой информации в сравнении с КТ сердца, кардио-МРТ не является методом выбора в первичной диагностике и предоперационном планировании коррекции КоАо у детей до года и младшей возрастной группы, требующих применения анестезиологического пособия на время сканирования

From nonassociativity to solutions of the KP hierarchy

A recently observed relation between 'weakly nonassociative' algebras A (for which the associator (A,A^2,A) vanishes) and the KP hierarchy (with dependent variable in the middle nucleus A' of A) is recalled. For any such algebra there is a nonassociative hierarchy of ODEs, the solutions of which determine solutions of the KP hierarchy. In a special case, and with A' a matrix algebra, this becomes a matrix Riccati hierarchy which is easily solved. The matrix solution then leads to solutions of the scalar KP hierarchy. We discuss some classes of solutions obtained in this way.Comment: 7 pages, 4 figures, International Colloquium 'Integrable Systems and Quantum Symmetries', Prague, 15-17 June 200

Quantum vortices in systems obeying a generalized exclusion principle

The paper deals with a planar particle system obeying a generalized exclusion principle (EP) and governed, in the mean field approximation, by a nonlinear Schroedinger equation. We show that the EP involves a mathematically simple and physically transparent mechanism, which allows the genesis of quantum vortices in the system. We obtain in a closed form the shape of the vortices and investigate its main physical properties. PACS numbers: 03.65.-w, 03.65.Ge, 05.45.YvComment: 7 pages, 4 figure

Photon- and meson-induced reactions on the nucleon

In an unitary effective Lagrangian model we develop a unified description of both meson scattering and photon-induced reactions on the nucleon. Adding the photon to an already existing model for meson-nucleon scattering yields both Compton and meson photoproduction amplitudes. In a simultaneous fit to all available data involving the final states $\gamma N$, $\pi N$, $\pi\pi N$, $\eta N$ and $K \Lambda$ the parameters of the nucleon resonances are extracted.Comment: 57 pages, 14 figures, LaTex (uses Revtex and graphicx). Submitted to Phys. Rev. C. References updated, Fig. 14 change

Vortex solitons - Mass, Energy and Angular momentum bunching in relativistic electron-positron plasmas

It is shown that the interaction of large amplitude electromagnetic waves with a hot electron-positron (e-p) plasma (a principal constituent of the universe in the MeV epoch) leads to a bunching of mass, energy, and angular momentum in stable, long-lived structures. Electromagnetism in the MeV epoch, then, could provide a possible route for seeding the observed large-scale structure of the universe.Comment: 17 pages with 2 figure

Transverse momentum spectra of charged particles in proton-proton collisions at s=900\sqrt{s} = 900 GeV with ALICE at the LHC

The inclusive charged particle transverse momentum distribution is measured in proton-proton collisions at $\sqrt{s} = 900$ GeV at the LHC using the ALICE detector. The measurement is performed in the central pseudorapidity region $(|\eta|<0.8)$ over the transverse momentum range $0.15<p_{\rm T}<10$ GeV/$c$. The correlation between transverse momentum and particle multiplicity is also studied. Results are presented for inelastic (INEL) and non-single-diffractive (NSD) events. The average transverse momentum for $|\eta|<0.8$ is $\left<p_{\rm T}\right>_{\rm INEL}=0.483\pm0.001$ (stat.) $\pm0.007$ (syst.) GeV/$c$ and \left_{\rm NSD}=0.489\pm0.001 (stat.) $\pm0.007$ (syst.) GeV/$c$, respectively. The data exhibit a slightly larger $\left<p_{\rm T}\right>$ than measurements in wider pseudorapidity intervals. The results are compared to simulations with the Monte Carlo event generators PYTHIA and PHOJET.Comment: 20 pages, 8 figures, 2 tables, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/390