11,892 research outputs found

    Theoretical description of the J/ψ→η(η′)h1(1380)\boldsymbol{J/\psi \to \eta (\eta') h_1(1380)}, J/ψ→η(η′)h1(1170)\boldsymbol{J/\psi \to \eta (\eta') h_1(1170)} and J/ψ→π0b1(1235)0\boldsymbol{J/\psi \to \pi^0 b_1(1235)^0} reactions

    Full text link
    We have made a study of the J/ψ→η′h1,ηh1J/\psi \to \eta' h_1, \eta h_1 (with h1h_1 being h1(1170)h_1(1170) and h1(1380)h_1(1380)) and J/ψ→π0b1(1235)0J/\psi \to \pi^0 b_1(1235)^0 assuming the axial vector mesons to be dynamically generated from the pseudoscalar-vector meson interaction. We have taken the needed input from previous studies of the J/ψ→ϕππ,ωππJ/\psi \to \phi \pi \pi, \omega \pi \pi reactions. We obtain fair agreement with experimental data and provide an explanation on why the recent experiment on J/ψ→η′h1(1380),h1(1380)→K∗+K−+c.c.J/\psi \to \eta' h_1(1380), h_1(1380) \to K^{*+} K^- +c.c. observed in the K+K−π0K^+ K^- \pi^0 mode observes the peak of the h1(1380)h_1(1380) at a higher energy than its nominal mass.Comment: 21 pages, 6 figure

    On Dust Extinction of Gamma-ray Burst Host Galaxies

    Get PDF
    Although it is well recognized that gamma-ray burst (GRB) afterglows are obscured and reddened by dust in their host galaxies, the wavelength-dependence and quantity of dust extinction are still poorly known. Current studies on this mostly rely on fitting the afterglow spectral energy distributions (SEDs) with template extinction models. The inferred extinction (both quantity and wavelength-dependence) and dust-to-gas ratios are often in disagreement with that obtained from dust depletion and X-ray spectroscopy studies. We argue that this discrepancy could result from the prior assumption of a template extinction law. We propose an analytical formula to approximate the GRB host extinction law. With the template extinction laws self-contained, and the capability of revealing extinction laws differing from the conventional ones, it is shown that this is a powerful approach in modeling the afterglow SEDs to derive GRB host extinction.Comment: 9 pages, 4 figures; The Astrophysical Journal, in press (2008 Oct 1 issue

    Transmission characteristics of a Fabry-Perot etalon-microtoroid resonator coupled system

    Get PDF
    The transmission spectra of a Fabry-Perot etalon coupled to a microtoroid resonator are studied theoretically and experimentally. The resonance line shapes depend strongly on the resonance wavelength detuning and coupling strength between the two resonators. A wide variety of line shapes, ranging from a single to triple peaks, symmetric to asymmetric Fano-like peaks, and notches were predicted and observed experimentally. The capability to modify the spectral line shapes by tuning the coupling between or losses of two resonators may find applications in optical filtering, switching, sensing, and dispersion engineering

    Combined electromagnetic and photoreaction modeling of CLD-1 photobleaching in polymer microring resonators

    Get PDF
    By combining a solid-state photoreaction model with the modal solutions of an optical waveguide, we simulate the refractive index change due to the photobleaching of CLD-1 chromophores in an amorphous polycarbonate microring resonator. The simulation agrees well with experimental results. The photobleaching quantum efficiency of the CLD-1 chromophores is determined to be 0.65%. The combined modeling of the electromagnetic wave propagation and photoreaction precisely illustrates the spatial and temporal evolution of the optical properties of the polymer material as manifested in the refractive index and their effects on the modal and physical properties of the optical devices

    Privacy Preserving Utility Mining: A Survey

    Full text link
    In big data era, the collected data usually contains rich information and hidden knowledge. Utility-oriented pattern mining and analytics have shown a powerful ability to explore these ubiquitous data, which may be collected from various fields and applications, such as market basket analysis, retail, click-stream analysis, medical analysis, and bioinformatics. However, analysis of these data with sensitive private information raises privacy concerns. To achieve better trade-off between utility maximizing and privacy preserving, Privacy-Preserving Utility Mining (PPUM) has become a critical issue in recent years. In this paper, we provide a comprehensive overview of PPUM. We first present the background of utility mining, privacy-preserving data mining and PPUM, then introduce the related preliminaries and problem formulation of PPUM, as well as some key evaluation criteria for PPUM. In particular, we present and discuss the current state-of-the-art PPUM algorithms, as well as their advantages and deficiencies in detail. Finally, we highlight and discuss some technical challenges and open directions for future research on PPUM.Comment: 2018 IEEE International Conference on Big Data, 10 page
    • …
    corecore