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

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

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

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

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

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 $\Omega$ 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 χc0,1,2→KKˉπ+π−\chi_{c0,1,2}\to K\bar K \pi^+\pi^- and 2π+2π−2\pi^+2\pi^-

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, $\psi \to \gamma p\bar p, \gamma\Lambda\bar \Lambda, \gamma\Sigma \bar\Sigma, \gamma\Xi\bar \Xi$ channels provide a good place for studying baryon-antibaryon interactions; the double radiative decays $\psi\to\gamma\gamma V$ with $V\equiv \rho,\omega,\phi$ have a potential to provide information on the flavor content of any meson resonances (R) with positive charge parity ($C=+$) and mass above 1 GeV through $\psi\to\gamma R \to\gamma\gamma V$; $\psi(2S)\to\gamma\chi_{c0,1,2}$ with $\chi_{c0,1,2}\to K\bar K \pi^+\pi^-$ and $2\pi^+2\pi^-$ decays are good processes to study $\chi_{cJ}$ charmonium decays. Using the covariant tensor formalism, here we provide theoretical PWA formulae for these channels.Comment: 20 page

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

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

Annihilation contribution and B→a0π,f0KB\to a_0 \pi, f_0 K decays

We analyze the decays $B^0 \to a^\pm_0 \pi^\mp$ and $B^{-,0} \to f_0 K^{-,0}$ and show that within the factorization approximation a phenomenological consistent picture can be obtained. We show that in this approach the $O_6$ operator provides the dominant contributions to the suppressed channel $B^0 \to a^+_0 \pi^-$. When the $a_0$ is considered a two quark state, evaluation of the annihilation form factor using Perturbative $QCD$ 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 $B^0 \to \pi^+ a_0^-$ can not distinguish between the two or four quark assignment of the $a_0$. According to our calculation, a best candidate to distinguish the nature of $a_0$ scalar is $Br(B^-\to \pi^0a_0^-)$ 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

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

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

Phonon-assisted tunneling in interacting suspended single wall carbon nanotubes

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

A review of the decoherent histories approach to the arrival time problem in quantum theory

We review recent progress in understanding the arrival time problem in quantum mechanics, from the point of view of the decoherent histories approach to quantum theory. We begin by discussing the arrival time problem, focussing in particular on the role of the probability current in the expected classical solution. After a brief introduction to decoherent histories we review the use of complex potentials in the construction of appropriate class operators. We then discuss the arrival time problem for a particle coupled to an environment, and review how the arrival time probability can be expressed in terms of a POVM in this case. We turn finally to the question of decoherence of the corresponding histories, and we show that this can be achieved for simple states in the case of a free particle, and for general states for a particle coupled to an environment.Comment: 10 pages. To appear in DICE 2010 conference proceeding