21,721 research outputs found

    Generation of time-bin entangled photons without temporal post-selection

    Full text link
    We report on the implementation of a new interferometric scheme that allows the generation of photon pairs entangled in the time-energy degree of freedom. This scheme does not require any kind of temporal post-selection on the generated pairs and can be used even with lasers with short coherence time.Comment: RevTex, 6 pages, 8 figure

    Alternativas para o manejo de lebres em pomares de citros.

    Get PDF
    bitstream/item/31083/1/COMUNICADO-135.pd

    The complete catalogue of gamma-ray bursts observed by the Wide Field Cameras on board BeppoSAX

    Full text link
    We present the complete on-line catalogue of gamma-ray bursts observed by the two Wide Field Cameras on board \sax in the period 1996-2002. Our aim is to provide the community with the largest published data set of GRB's prompt emission X-ray light curves and other useful data. This catalogue (BS-GRBWFCcat) contains data on 77 bursts and a collection of the X-ray light curves of 56 GRB discovered or noticed shortly after the event and of other additional bursts detected in subsequent searches. Light curves are given in the three X-ray energy bands (2-5, 5-10, 10-26 keV). The catalogue can be accessed from the home web page of the ASI Science Data Center-ASDC (http://www.asdc.asi.it)Comment: 4 pages, 3 figure

    Heavy-flavor dynamics in nucleus-nucleus collisions: from RHIC to LHC

    Get PDF
    The stochastic dynamics of c and b quarks in the fireball created in nucleus-nucleus collisions at RHIC and LHC is studied employing a relativistic Langevin equation, based on a picture of multiple uncorrelated random collisions with the medium. Heavy-quark transport coefficients are evaluated within a pQCD approach, with a proper HTL resummation of medium effects for soft scatterings. The Langevin equation is embedded in a multi-step setup developed to study heavy-flavor observables in pp and AA collisions, starting from a NLO pQCD calculation of initial heavy-quark yields, complemented in the nuclear case by shadowing corrections, k_T-broadening and nuclear geometry effects. Then, only for AA collisions, the Langevin equation is solved numerically in a background medium described by relativistic hydrodynamics. Finally, the propagated heavy quarks are made hadronize and decay into electrons. Results for the nuclear modification factor R_AA of heavy-flavor hadrons and electrons from their semi-leptonic decays are provided, both for RHIC and LHC beam energies.Comment: 4 pages, 2 figures (3 eps files); submitted for publication in the proceedings of "Quark Matter 2011", 23-28 May 2011, Annecy (France

    An Atypical Cutaneous Reaction to Rivastigmine Transdermal Patch

    Get PDF
    Rivastigmine is a cholinesterase inhibitor which improves cognitive function and is currently being used in patients with mild to moderate Parkinson's and Alzheimer's dementia. This drug can be given orally or topically, as transdermal patch. The latter form is currently used for most excellent compliance and few side effects. The most common cutaneous side effects are irritative dermatitis. We report the second case of active sensitization by the rivastigmine-patch in a patient suffering from Alzheimer's dementia

    Computing Topology Preservation of RBF Transformations for Landmark-Based Image Registration

    Full text link
    In image registration, a proper transformation should be topology preserving. Especially for landmark-based image registration, if the displacement of one landmark is larger enough than those of neighbourhood landmarks, topology violation will be occurred. This paper aim to analyse the topology preservation of some Radial Basis Functions (RBFs) which are used to model deformations in image registration. Mat\'{e}rn functions are quite common in the statistic literature (see, e.g. \cite{Matern86,Stein99}). In this paper, we use them to solve the landmark-based image registration problem. We present the topology preservation properties of RBFs in one landmark and four landmarks model respectively. Numerical results of three kinds of Mat\'{e}rn transformations are compared with results of Gaussian, Wendland's, and Wu's functions

    πNN\pi NN coupling determined beyond the chiral limit

    Get PDF
    Within the conventional QCD sum rules, we calculate the πNN\pi NN coupling constant, gπNg_{\pi N}, beyond the chiral limit using two-point correlation function with a pion. We consider the Dirac structure, iγ5i\gamma_5, at mπ2m_\pi^2 order, which has clear dependence on the PS and PV coupling schemes for the pion-nucleon interactions. For a consistent treatment of the sum rule, we include the linear terms in quark mass as they constitute the same chiral order as mπ2m_\pi^2. Using the PS coupling scheme for the pion-nucleon interaction, we obtain gπN=13.3±1.2g_{\pi N}=13.3\pm 1.2, which is very close to the empirical πNN\pi NN coupling. This demonstrates that going beyond the chiral limit is crucial in determining the coupling and the pseudoscalar coupling scheme is preferable from the QCD point of view.Comment: 8 pages, revtex, some errors are corrected, substantially revise

    Stability and collisions of moving semi-gap solitons in Bragg cross-gratings

    Full text link
    We report results of a systematic study of one-dimensional four-wave moving solitons in a recently proposed model of the Bragg cross-grating in planar optical waveguides with the Kerr nonlinearity; the same model applies to a fiber Bragg grating (BG) carrying two polarizations of light. We concentrate on the case when the system's spectrum contains no true bandgap, but only semi-gaps (which are gaps only with respect to one branch of the dispersion relation), that nevertheless support soliton families. Solely zero-velocity solitons were previously studied in this system, while current experiments cannot generate solitons with the velocity smaller than half the maximum group velocity. We find the semi-gaps for the moving solitons in an analytical form, and demonstrated that they are completely filled with (numerically found) solitons. Stability of the moving solitons is identified in direct simulations. The stability region strongly depends on the frustration parameter, which controls the difference of the present system from the usual model for the single BG. A completely new situation is possible, when the velocity interval for stable solitons is limited not only from above, but also from below. Collisions between stable solitons may be both elastic and strongly inelastic. Close to their instability border, the solitons collide elastically only if their velocities c1 and c2 are small; however, collisions between more robust solitons are elastic in a strip around c1=-c2.Comment: 16 pages, 7 figures, Physics Letters A, in pres
    • …
    corecore