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Articles 1 - 11 of 11
Full-Text Articles in Physics
Tetraquark Operators In Lattice Qcd And Exotic Flavour States In The Charm Sector, Gavin K. C. Cheung, Christopher E. Thomas, Jozef J. Dudek, Robert G. Edwards
Tetraquark Operators In Lattice Qcd And Exotic Flavour States In The Charm Sector, Gavin K. C. Cheung, Christopher E. Thomas, Jozef J. Dudek, Robert G. Edwards
Arts & Sciences Articles
We present a general class of operators resembling compact tetraquarks which have a range of colour-flavour-spin structures, transform irreducibly under the symmetries of the lattice and respect other relevant symmetries. These constructions are demonstrated in lattice QCD calculations with light quarks corresponding to m(pi) = 391 MeV. Using the distillation framework, correlation functions involving large bases of meson-meson and tetraquark operators are computed in the isospin-1 hidden-charm and doubly-charmed sectors, and finite-volume spectra are extracted with the variational method. We find the spectra are insensitive to the addition of tetraquark operators to the bases of meson-meson operators. For the first …
First Measurement Of Proton's Charge Form Factor At Very Low Q(2) With Initial State Radiation, M. Mihovilovic, K. Griffioen, Et Al.
First Measurement Of Proton's Charge Form Factor At Very Low Q(2) With Initial State Radiation, M. Mihovilovic, K. Griffioen, Et Al.
Arts & Sciences Articles
We report on a new experimental method based on initial-state radiation (ISR) in e-p scattering, which exploits the radiative tail of the elastic peak to study the properties of electromagnetic processes and to extract the proton charge form factor (G(E)(P)) at extremely small Q(2). The ISR technique was implemented in an experiment at the three-spectrometer facility of the Mainz Microtron (MAMI). This led to a precise validation of radiative corrections far away from elastic line and provided first measurements of G(E)(P) for 0.001 <= Q(2) <= 0.004 (GeV/c)(2). (C) 2017 The Authors. Published by Elsevier B.V.
Drifts, Currents, And Power Scrape-Off Width In Solps-Iter Modeling Of Diii-D, E. T. Meier, R. J. Goldston, E. G. Kaveeva, M. A. Makowski, S. Mordijck
Drifts, Currents, And Power Scrape-Off Width In Solps-Iter Modeling Of Diii-D, E. T. Meier, R. J. Goldston, E. G. Kaveeva, M. A. Makowski, S. Mordijck
Arts & Sciences Articles
The effects of drifts and associated flows and currents on the width of the parallel heat flux channel (lambda(q)) in the tokamak scrape-offlayer (SOL) are analyzed using the SOLPS-ITER 2D fluid transport code. Motivation is supplied by Goldston's heuristic drift (HD) model for lambda(q), which yields the same approximately inverse poloidal magnetic field dependence seen in multi-machine regression. The analysis, focusing on a DIII-D H-mode discharge, reveals HD-like features, including comparable density and temperature fall-off lengths in the SOL, and up-down ion pressure asymmetry that allows net cross-separatrix ion magnetic drift flux to exceed net anomalous ion flux. In experimentally …
Broadband Near-Field Infrared Spectroscopy With A High Temperature Plasma Light Source, D. J. Lahneman, T. J. Huffman, Peng Xu, M. M. Qazilbash
Broadband Near-Field Infrared Spectroscopy With A High Temperature Plasma Light Source, D. J. Lahneman, T. J. Huffman, Peng Xu, M. M. Qazilbash
Arts & Sciences Articles
Scattering-type scanning near-field optical microscopy (S-SNOM) has enormous potential as a spectroscopy tool in the infrared spectral range where it can probe phonon resonances and carrier dynamics at the nanometer lengths scales. However, its applicability is limited by the lack of practical and affordable table-top light sources emitting intense broadband infrared radiation in the 100 cm(-1) to 2,500 cm(-1) spectral range. This paper introduces a high temperature plasma light source that is both ultra-broadband and has much more radiant power in the infrared spectral range than conventional, table-top thermal light sources such as the globar. We implement this plasma lamp …
Isovector Charges Of The Nucleon From 2+1-Flavor Qcd With Clover Fermions, Boram Yoon, Yong-Chull Jang, (...), Kostas Orginos, Et Al.
Isovector Charges Of The Nucleon From 2+1-Flavor Qcd With Clover Fermions, Boram Yoon, Yong-Chull Jang, (...), Kostas Orginos, Et Al.
Arts & Sciences Articles
We present high-statistics estimates of the isovector charges of the nucleon from four 2 + 1-flavor ensembles generated using Wilson-clover fermions with stout smearing and tree-level tadpole improved Symanzik gauge action at lattice spacings a approximate to 0.127 and 0.09 fm and with M-pi approximate to 280 and 170 MeV. The truncated solver method with bias correction and the coherent source sequential propagator construction are used to cost-effectively achieve O (10(5)) measurements on each ensemble. Using these data, the analysis of two-point correlation functions is extended to include four states in the fits, and of three-point functions to three states. …
Measurement Of The Beam Asymmetry Sigma For Pi(0) And Eta Photoproduction On The Proton At E-Gamma=9 Gev, H. Al Ghoul, (...), Justin R. Stevens, Et Al.
Measurement Of The Beam Asymmetry Sigma For Pi(0) And Eta Photoproduction On The Proton At E-Gamma=9 Gev, H. Al Ghoul, (...), Justin R. Stevens, Et Al.
Arts & Sciences Articles
We report measurements of the photon beam asymmetry Sigma for the reactions (gamma) over right arrowp -> p pi(0) and gamma p -> p eta from the GLUEX experiment using a 9 GeV linearly polarized, tagged photon beam incident on a liquid hydrogen target in Jefferson Lab's Hall D. The asymmetries, measured as a function of the proton momentum transfer, possess greater precision than previous pi(0) measurements and are the first. measurements in this energy regime. The results are compared with theoretical predictions based on t-channel, quasiparticle exchange and constrain the axial-vector component of the neutral meson production mechanism in …
Squeezing Light With Atoms: Generation Of Non-Classical Light Via Four-Wave Mixing, Nathan Super
Squeezing Light With Atoms: Generation Of Non-Classical Light Via Four-Wave Mixing, Nathan Super
Science Research Symposium
The goal of the project is to produce a pair of polarization-entangled light fields using four-wave mixing in hot Rb vapor. In this process, interaction of atoms with near-resonant strong control optical field results in strong amplification of a nearly-collinear probe optical field and in generation of a quantum correlated conjugate Stokes optical field. In order to establish the quantum correlation between the Stokes and probe fields, we have adopted a homodyne detection scheme. If the differential noise between the Stokes and probe fields is below the quantum noise limit, then intensity fluctuation entanglement has been achieved, and it is …
Hampton Roads Crossing Study Supplemental Environmental Impact Statement: Evaluation Of Potential Impact On Surface Water Elevation, Flow, Salinity, And Bottom Shear Stress, Yinglong J. Zhang, Harry V. Wang, Zhuo Liu, Mac Sisson, Jian Shen
Hampton Roads Crossing Study Supplemental Environmental Impact Statement: Evaluation Of Potential Impact On Surface Water Elevation, Flow, Salinity, And Bottom Shear Stress, Yinglong J. Zhang, Harry V. Wang, Zhuo Liu, Mac Sisson, Jian Shen
Reports
The purpose of this study is to evaluate the potential impacts of the proposed alternatives for the highway crossing in Hampton Roads on physical characteristics of surface water elevation, flow, salinity, and bottom shear stress. The analysis is part of the Virginia Department of Transportation (VDOT), the Federal Highway Administration, and other stakeholders’ Supplemental Environmental Impact Statement (SEIS) for Hampton Roads Crossing Study (HRCS).
Isoscalar Pi Pi Scattering And The Sigma Meson Resonance From Qcd, Raul A. Briceño, Jozef J. Dudek, Robert G. Edwards, David J. Wilson
Isoscalar Pi Pi Scattering And The Sigma Meson Resonance From Qcd, Raul A. Briceño, Jozef J. Dudek, Robert G. Edwards, David J. Wilson
Arts & Sciences Articles
We present for the first time a determination of the energy dependence of the isoscalar pi pi elastic scattering phase shift within a first-principles numerical lattice approach to QCD. Hadronic correlation functions are computed including all required quark propagation diagrams, and from these the discrete spectrum of states in the finite volume defined by the lattice boundary is extracted. From the volume dependence of the spectrum, we obtain the S-wave phase shift up to the K (K) over bar threshold. Calculations are performed at two values of the u, d quark mass corresponding to m(pi) = 236; 391 MeV, and …
Q(Weak): First Direct Measurement Of The Proton's Weak Charge, J. F. Dowd
Q(Weak): First Direct Measurement Of The Proton's Weak Charge, J. F. Dowd
Arts & Sciences Articles
The Q(weak) experiment, which took data at Jefferson Lab in the period 2010 - 2012, will precisely determine the weak charge of the proton by measuring the parity-violating asymmetry in elastic e-p scattering at 1.1 GeV using a longitudinally polarized electron beam and a liquid hydrogen target at a low momentum transfer of Q(2) = 0.025 ( GeV/c)(2). The weak charge of the proton is predicted by the Standard Model and any significant deviation would indicate physics beyond the Standard Model. The technical challenges and experimental apparatus for measuring the weak charge of the proton will be discussed, as well …
Multispectrum Analysis Of The Oxygen A-Band, Brian J. Drouin, D. Chris Benner, Linda R. Brown, (...), V. Malathy Devi, Et Al.
Multispectrum Analysis Of The Oxygen A-Band, Brian J. Drouin, D. Chris Benner, Linda R. Brown, (...), V. Malathy Devi, Et Al.
Arts & Sciences Articles
Retrievals of atmospheric composition from near-infrared measurements require measurements of airmass to better than the desired precision of the composition. The oxygen bands are obvious choices to quantify airmass since the mixing ratio of oxygen is fixed over the full range of atmospheric conditions. The OCO-2 mission is currently retrieving carbon dioxide concentration using the oxygen A-band for airmass normalization. The 0.25% accuracy desired for the carbon dioxide concentration has pushed the required state-of-the-art for oxygen spectroscopy. To measure 02 A-band cross-sections with such accuracy through the full range of atmospheric pressure requires a sophisticated line shape model (Rautian or …