11,974 research outputs found

    New measurements of the proton's size and structure using polarized photons

    Full text link
    Improved measurements of the proton's structure are now possible thanks to significant technical advances that allow us to probe the proton with polarized photons. These measurements have shown that the proton is not as simple as previously believed: quark orbital angular momentum and relativistic effects play an important role and the spatial distribution of charge and magnetization do not simply mimic the spatial distribution of the quarks. Even more recently, the large scale structure and size of the proton have been examined more carefully, and a significant discrepancy has been observed between the charge radius of the proton as measured in the Lamb shift of muonic hydrogen and measurements using the electron-proton interaction.Comment: 8 pages, 3 figures. Proceedings of plenary talk at CIPANP 2012, St Petersburg, FL, May 28 - June 3, 201

    Scanning the issue: T-ray imaging, sensing, and retection

    Get PDF
    Copyright © 2007 IEEEDerek Abbott, Xi-Cheng Zhan

    J/ψ+jetJ/\psi + jet diffractive production in the direct photon process at HERA

    Full text link
    We present a study of J/ψ+jetJ/\psi + jet diffractive production in the direct photon process at HERA based on the factorization theorem for lepton-induced hard diffractive scattering and the factorization formalism of the nonrelativistic QCD (NRQCD) for quarkonia production. Using the diffractive gluon distribution function extracted from HERA data on diffractive deep inelastic scattering and diffractive dijet photon production, we show that this process can be studied at HERA with present integrated luminosity, and can give valuable insights in the color-octet mechanism for heavy quarkonia production.Comment: Revtex, 21 pages, 7 EPS figure

    Comment on 'Nanoscale mapping of optical band gaps using monochromated electron energy loss spectroscopy' by Zhan, Granerød, Venkatachalapathy, Johansen, Jensen, Kuznetsov and Prytz in Nanotechnology 28 (2017) 105703

    Get PDF
    Comment on ‘Nanoscale mapping of optical band gaps using monochromated electron energy loss spectroscopy’ by Zhan, Granerød, Venkatachalapathy, Johansen, Jensen, Kuznetsov and Prytz in Nanotechnology 28 (2017) 10570

    A new approach to the study of the ground-state properties of 2D Ising spin glass

    Full text link
    A new approach known as flat histogram method is used to study the +/-J Ising spin glass in two dimensions. Temperature dependence of the energy, the entropy, and other physical quantities can be easily calculated and we give the results for the zero-temperature limit. For the ground-state energy and entropy of an infinite system size, we estimate e0 = -1.4007 +/- 0.0085 and s0 = 0.0709 +/- 0.006, respectively. Both of them agree well with previous calculations. The time to find the ground-states as well as the tunneling times of the algorithm are also reported and compared with other methods.Comment: 11 pages, 4 figure
    corecore