2,877 research outputs found

    A Study Of A New Class Of Discrete Nonlinear Schroedinger Equations

    Full text link
    A new class of 1D discrete nonlinear Schro¨{\ddot{\rm{o}}}dinger Hamiltonians with tunable nonlinerities is introduced, which includes the integrable Ablowitz-Ladik system as a limit. A new subset of equations, which are derived from these Hamiltonians using a generalized definition of Poisson brackets, and collectively refered to as the N-AL equation, is studied. The symmetry properties of the equation are discussed. These equations are shown to possess propagating localized solutions, having the continuous translational symmetry of the one-soliton solution of the Ablowitz-Ladik nonlinear Schro¨{\ddot{\rm{o}}}dinger equation. The N-AL systems are shown to be suitable to study the combined effect of the dynamical imbalance of nonlinearity and dispersion and the Peierls-Nabarro potential, arising from the lattice discreteness, on the propagating solitary wave like profiles. A perturbative analysis shows that the N-AL systems can have discrete breather solutions, due to the presence of saddle center bifurcations in phase portraits. The unstaggered localized states are shown to have positive effective mass. On the other hand, large width but small amplitude staggered localized states have negative effective mass. The collison dynamics of two colliding solitary wave profiles are studied numerically. Notwithstanding colliding solitary wave profiles are seen to exhibit nontrivial nonsolitonic interactions, certain universal features are observed in the collison dynamics. Future scopes of this work and possible applications of the N-AL systems are discussed.Comment: 17 pages, 15 figures, revtex4, xmgr, gn

    Interplay of quark and meson degrees of freedom in a near-threshold resonance

    Get PDF
    We investigate the interplay of quark and meson degrees of freedom in a physical state representing a near-threshold resonance for the case of a single continuum channel. We demonstrate that such a near-threshold resonance may possess quite peculiar properties if both quark and meson dynamics generate weakly coupled near-threshold poles in the S-matrix. In particular, the scattering t-matrix may possess zeros in this case. We also discuss possible implications for production reactions as well as studies within lattice QCD.Comment: LaTeX2e, 11 pages, minor typo corrections, to appear in Eur.Phys.J.

    Near-threshold production of a0(980)a_0(980)-mesons in πN\pi N and NN collisions and a0/f0a_0/f_0-mixing

    Get PDF
    We consider near-threshold a0(980)a_0(980)-meson production in πN\pi N and NNNN collisions. An effective Lagrangian approach with one-pion exchange is applied to analyze different contributions to the cross section for different isospin channels. The Reggeon exchange mechanism is also evaluated for comparison. The results from πN\pi N reactions are used to calculate the contribution of the a0a_0 meson to the cross sections and invariant KKˉK \bar K mass distributions of the reactions pppnK+Kˉ0pp\to pn K^+\bar K^0 and ppppK+Kpp\to pp K^+K^-. It is found that the experimental observation of a0+a_0^+ mesons in the reaction pppnK+Kˉ0pp\to pn K^+\bar K^0 is much more promising than the observation of a00a_0^0 mesons in the reaction ppppK+Kpp\to pp K^+K^-. Effects of isospin violation in the reactions pNda0pN \to d a_0, pd3He/3Ha0pd \to \mathrm{^3He/^3H} a_0, and dd4Hea0 dd \to \mathrm{^4He} a_0, which are induced by a0(980)a_0(980)--f0(980)f_0(980) mixing, are also analyzed.Comment: 43 pages, including 16 eps figures, to be bublished in Phys. Atom. Nucl. (Yad. Fiz.) vol. 65, No. 11 (2002

    Возможности применения технологии блокчейн при перевозке грузов в международном сообщении

    Get PDF
    For the English abstract and full text of the article please see the attached PDF-File (English version follows Russian version).ABSTRACT The main difficulties in transportation of goods with international container trains arise at state border crossing points. A detailed analysis of the reasons for their delays at the railway checkpoints revealed the most characteristic «narrow» places. In order to improve the procedures for documenting and informational support of cargo flows, as well as to consolidate business processes involving cargo owners, carriers, forwarders, federal authorities in the sphere of control and supervision, companies providing transportation and logistics services, it was proposed to create a single information environment with the technology of block chain. The authors identify possible financial results of its implementation, as well as reveal new software resources that can be developed on the basis of business logic tools involved in evaluation of the quality of goods movement on the transport route. Keywords: container traffic, international delivery, transport route, railway border crossing point, block chain.Текст аннотации на англ. языке и полный текст статьи на англ. языке находится в прилагаемом файле ПДФ (англ. версия следует после русской версии).Основные затруднения при транспортировке грузов международными контейнерными поездами возникают при пересечении государственной границы. Детальный анализ причин их задержек на железнодорожных пунктах пропуска выявил наиболее характерные «узкие» места. В целях совершенствования процедур документального и информационного сопровождения грузопотоков, а также консолидации бизнес-процессов с участием грузовладельцев, перевозчиков, экспедиторов, федеральных органов исполнительной власти в сфере контроля и надзора, компаний по предоставлению транспортных и логистических услуг предложено создание единого информационного пространства по технологии блокчейн (block chain). Определены финансовые результаты его использования, найдены дополнительные ресурсы программного продукта на основе инструментов бизнес-логики, причастных к оценке качества товародвижения на транспортном маршруте

    Early onset of ground-state deformation in the neutron-deficient polonium isotopes

    Full text link
    In-source resonant ionization laser spectroscopy of the even-AA polonium isotopes 192210,216,218^{192-210,216,218}Po has been performed using the 6p37s6p^37s 5S2^5S_2 to 6p37p6p^37p 5P2^5P_2 (λ=843.38\lambda=843.38 nm) transition in the polonium atom (Po-I) at the CERN ISOLDE facility. The comparison of the measured isotope shifts in 200210^{200-210}Po with a previous data set allows to test for the first time recent large-scale atomic calculations that are essential to extract the changes in the mean-square charge radius of the atomic nucleus. When going to lighter masses, a surprisingly large and early departure from sphericity is observed, which is only partly reproduced by Beyond Mean Field calculations.Comment: As submitted to PR

    Precise measurement of RudsR_{\text{uds}} and RR between 1.84 and 3.72 GeV at the KEDR detector

    Full text link
    The present work continues a series of the KEDR measurements of the RR value that started in 2010 at the VEPP-4M e+ee^+e^- collider. By combining new data with our previous results in this energy range we measured the values of RudsR_{\text{uds}} and RR at nine center-of-mass energies between 3.08 and 3.72 GeV. The total accuracy is about or better than 2.6%2.6\% at most of energy points with a systematic uncertainty of about 1.9%1.9\%. Together with the previous precise RR measurement at KEDR in the energy range 1.84-3.05 GeV, it constitutes the most detailed high-precision RR measurement near the charmonium production threshold.Comment: arXiv admin note: text overlap with arXiv:1610.02827 and substantial text overlap with arXiv:1510.0266
    corecore