9,599,933 research outputs found

    Amplitude equations for a linear wave equation in a weakly curved pipe

    Full text link
    We study boundary effects in a linear wave equation with Dirichlet type conditions in a weakly curved pipe. The coordinates in our pipe are prescribed by a given small curvature with finite range, while the pipe's cross section being circular. Based on the straight pipe case a perturbative analysis by which the boundary value conditions are exactly satisfied is employed. As such an analysis we decompose the wave equation into a set of ordinary differential equations perturbatively. We show the conditions when secular terms due to the curbed boundary appear in the naive peturbative analysis. In eliminating such a secularity with a singular perturbation method, we derive amplitude equations and show that the eigenfrequencies in time are shifted due to the curved boundary.Comment: To appear in J Phys A: Math. Theo

    Singular and Half-Quantum Vortices and Associated Majorana Particles in Superfluid 3He-A between Parallel Plates

    Full text link
    Motivated by a recent experiment on superfluid 3He-A confined in narrow parallel plates using a rotating cryostat, we explore possible vortices stable under magnetic field applied to arbitrary angle relative to the plates in order to seek vortices which can accommodate the Majorana zero mode in the core. After proving that the singular vortex with the unit winding number provides the Majorana mode in the spinful situation, we establish the phase diagram in the plane; the rotation frequency Ω\Omega vs system size R by finding possible order parameter textures within the Ginzburg-Landau framework. We also analyze the stability for a single and a pair of half-quantum vortices, which possesses the Majorana mode in its core. It is concluded from the above mention that the Majorana zero mode can be found in the present on-going experimental setting at ISSP, Univ. Tokyo.Comment: 9 pages, 15 figure

    Covariant tensor formalism for partial wave analyses of ψ\psi decays into γBBˉ\gamma B\bar B, γγV\gamma\gamma V and ψ(2S)γχc0,1,2\psi(2S)\to\gamma\chi_{c0,1,2} with χc0,1,2KKˉπ+π\chi_{c0,1,2}\to K\bar K \pi^+\pi^- and 2π+2π2\pi^+2\pi^-

    Full text link
    With accumulation of high statistics data at BES and CLEO-c, many new interesting channels can get enough statistics for partial wave analysis (PWA). Among them, ψγppˉ,γΛΛˉ,γΣΣˉ,γΞΞˉ\psi \to \gamma p\bar p, \gamma\Lambda\bar \Lambda, \gamma\Sigma \bar\Sigma, \gamma\Xi\bar \Xi channels provide a good place for studying baryon-antibaryon interactions; the double radiative decays ψγγV\psi\to\gamma\gamma V with Vρ,ω,ϕV\equiv \rho,\omega,\phi have a potential to provide information on the flavor content of any meson resonances (R) with positive charge parity (C=+C=+) and mass above 1 GeV through ψγRγγV\psi\to\gamma R \to\gamma\gamma V; ψ(2S)γχc0,1,2\psi(2S)\to\gamma\chi_{c0,1,2} with χc0,1,2KKˉπ+π\chi_{c0,1,2}\to K\bar K \pi^+\pi^- and 2π+2π2\pi^+2\pi^- decays are good processes to study χcJ\chi_{cJ} charmonium decays. Using the covariant tensor formalism, here we provide theoretical PWA formulae for these channels.Comment: 20 page

    Analyses of k_t distributions at RHIC by means of some selected statistical and stochastic models

    Get PDF
    The new data on k_t distributions obtained at RHIC are analysed by means of selected models of statistical and stochastic origin in order to estimate their importance in providing new information on hadronization process, in particular on the value of the temperature at freeze-out to hadronic phase.Comment: Modified version. One new figure, one new table and one reference addee

    Annihilation contribution and Ba0π,f0KB\to a_0 \pi, f_0 K decays

    Full text link
    We analyze the decays B0a0±πB^0 \to a^\pm_0 \pi^\mp and B,0f0K,0B^{-,0} \to f_0 K^{-,0} and show that within the factorization approximation a phenomenological consistent picture can be obtained. We show that in this approach the O6O_6 operator provides the dominant contributions to the suppressed channel B0a0+πB^0 \to a^+_0 \pi^-. When the a0a_0 is considered a two quark state, evaluation of the annihilation form factor using Perturbative QCDQCD implies that this contribution is not negligible, and furthermore it can interfere constructively or destructively with other penguin contributions. As a consequence of this ambiguity, the positive identification of B0π+a0B^0 \to \pi^+ a_0^- can not distinguish between the two or four quark assignment of the a0a_0. According to our calculation, a best candidate to distinguish the nature of a0a_0 scalar is Br(Bπ0a0)Br(B^-\to \pi^0a_0^-) since the predictions for a four quark model is one order of magnitude smaller than for the two quark assignment. When the scalars are seen as two quarks states, simple theoretical assumptions based on SU(2) isospin symmetry provide relations between different B decays involving one scalar and one pseudoscalar meson.Comment: 12 pages, 3 figure

    Boundary K-Matrices for the Six Vertex and the n(2n-1) A_{n-1} Vertex Models

    Full text link
    Boundary conditions compatible with integrability are obtained for two dimensional models by solving the factorizability equations for the reflection matrices K±(θ)K^{\pm}(\theta). For the six vertex model the general solution depending on four arbitrary parameters is found. For the An1A_{n-1} models all diagonal solutions are found. The associated integrable magnetic Hamiltonians are explicitly derived.Comment: 9 pages,latex, LPTHE-PAR 92-4

    Pengaruh Example Non Example terhadap Hasil Belajar Pkn Kelas IV Min Bangka Belitung

    Full text link
    A common problem in this research is “how is the influence of example non example model on student learning outcomes in the subject of civics education grade 4 Madrasah Ibtidaiyah Negeri Bangka Belitung Southeast Pontianak.study aims to find out how much influence example non example results on student learning outcomes on the subject of citizenship education grade 4 Madrasah Ibtidaiyah Negeri Bangka Belitung Southeast Pontianak. Research method is experimental method. The form of research used in this study is quasy experiment, with research design posstest only control design. Population in this study were all 4th graders Madrasah Ibtidaiyah Negeri Bangka Belitung Southeast Pontianak.which consists of two classes namely class 4A and 4B. The data collections instrument used is a measurement techniquean data collection tools in the form of text of students learning outcomes in the form of essay with the amountof 10 questions. Based on the calculation result obtained average pretest experiment class 33,56 and average pretest control class 26,5. Posttest experiment class 70,38 and posttest control class 62,25. Then form the calculation of t test obtained price = 1,6759. Evidently (2,8626) (1,6759), then accepted and rejected form the calculation effect size 0,82 belong to the high category, this means learning by applying the model example non example give influence to the result of learning of citizenship educations grade 4 Madrasah Ibtidaiyah Negeri Bangka Belitung Southeast Pontianak

    Example-based machine translation of the Basque language

    Get PDF
    Basque is both a minority and a highly inflected language with free order of sentence constituents. Machine Translation of Basque is thus both a real need and a test bed for MT techniques. In this paper, we present a modular Data-Driven MT system which includes different chunkers as well as chunk aligners which can deal with the free order of sentence constituents of Basque. We conducted Basque to English translation experiments, evaluated on a large corpus (270, 000 sentence pairs). The experimental results show that our system significantly outperforms state-of-the-art approaches according to several common automatic evaluation metrics

    Phonon-assisted tunneling in interacting suspended single wall carbon nanotubes

    Full text link
    Transport in suspended metallic single wall carbon nanotubes in the presence of strong electron-electron interaction is investigated. We consider a tube of finite length and discuss the effects of the coupling of the electrons to the deformation potential associated to the acoustic stretching and breathing modes. Treating the interacting electrons within the framework of the Luttinger liquid model, the low-energy spectrum of the coupled electron-phonon system is evaluated. The discreteness of the spectrum is reflected in the differential conductance which, as a function of the applied bias voltage, exhibits three distinct families of peaks. The height of the phonon-assisted peaks is very sensitive to the parameters. The phonon peaks are best observed when the system is close to the Wentzel-Bardeen singularity.Comment: 14 pages, 3 figure

    Example And Non-example Learning Model Berbantuan Media Poster untuk Menumbuhkan Kemampuan Koneksi Matematis Mahasiswa

    Full text link
    Proses belajar matematika yang dilakukan di program studi Pendidikan Matematika, Universitas Muhammadiyah Purwokerto, hendaknya mendukung kemampuan mahasiswa untuk mencari konsep dari belajar itu sendiri sebagai proses belajar mereka. Untuk menciptakan suasana belajar dimana mahasiswa dapat mencari ide dan konsep belajar matematika mereka sendiri perlu didukung oleh model pembelajaran yang dapat efektif untuk menyelesaikan masalah tersebut dan media pembelajaran guna alat bantu mahasiswa untuk memaksimalkan kemampuan matematika mereka. Penggunaan Example and Non-Example Learning Model dengan berbantuan media pemelajaran poster diharapkan dapat merubah kondisi belajar yang pasif menjadi aktif dan kreatif, menumbuhkembangkan kemampuan dalam pembelajaran secara umum, dan menciptakan kemampuan matematika secara khusus, seperti kemampuan koneksi matematika, serta mengubah pembelajaran yang teacher oriented ke student oriented. Oleh karena itu, dengan menggunakan Pembelajaran Example and Non-Example berbantuan media pembelajaran poster secara berulang-ulang di mata kuliah Teori Belajar dan Pembelajaran program studi Pendidikan Matematika Universitas Muhammadiyah Purwokerto diharapkan dapat menumbuhkan kemampuan koneksi matematika mahasiswa
    corecore