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Full-Text Articles in Physics

Isoscalar 𝜋𝜋 Scattering And The Σ Meson Resonance From Qcd, Raúl A. Briceño, Jozef J. Dudek, Robert G. Edwards, David J. Wilson Jan 2017

Isoscalar 𝜋𝜋 Scattering And The Σ Meson Resonance From Qcd, Raúl A. Briceño, Jozef J. Dudek, Robert G. Edwards, David J. Wilson

Physics Faculty Publications

We present for the first time a determination of the energy dependence of the isoscalar ππ 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 KK¯ threshold. Calculations are performed at two values of the u, d quark mass corresponding to mπ=236,391  MeV, and the resulting amplitudes …


Role Of The Euclidean Signature In Lattice Calculations Of Quasidistributions And Other Nonlocal Matrix Elements, Raúl A. Briceño, Maxwell T. Hansen, Christopher J. Monahan Jan 2017

Role Of The Euclidean Signature In Lattice Calculations Of Quasidistributions And Other Nonlocal Matrix Elements, Raúl A. Briceño, Maxwell T. Hansen, Christopher J. Monahan

Physics Faculty Publications

Lattice quantum chromodynamics (QCD) provides the only known systematic, nonperturbative method for first-principles calculations of nucleon structure. However, for quantities such as light-front parton distribution functions (PDFs) and generalized parton distributions (GPDs), the restriction to Euclidean time prevents direct calculation of the desired observable. Recently, progress has been made in relating these quantities to matrix elements of spatially nonlocal, zero-time operators, referred to as quasidistributions. Still, even for these time-independent matrix elements, potential subtleties have been identified in the role of the Euclidean signature. In this work, we investigate the analytic behavior of spatially nonlocal correlation functions and demonstrate that …


Relating The Finite-Volume Spectrum And The Two And Three-Particle S Matrix For Relativistic Systems Of Identical Scalar Particles, Raúl Briceño, Maxwell T. Hansen, Stephen R. Sharpe Jan 2017

Relating The Finite-Volume Spectrum And The Two And Three-Particle S Matrix For Relativistic Systems Of Identical Scalar Particles, Raúl Briceño, Maxwell T. Hansen, Stephen R. Sharpe

Physics Faculty Publications

Working in relativistic quantum field theory, we derive the quantization condition satisfied by coupled two- and three-particle systems of identical scalar particles confined to a cubic spatial volume with periodicity L. This gives the relation between the finite-volume spectrum and the infinite-volume 2 → 2, 2 → 3, and 3 → 3 scattering amplitudes for such theories. The result holds for relativistic systems composed of scalar particles with nonzero mass m, whose center of mass energy lies below the four-particle threshold, and for which the two-particle K matrix has no singularities below the three-particle threshold. The quantization condition is exact …


Anisotropic Thermodynamic And Transport Properties Of Single-Crystalline Cakfe4As4, W. R. Meier, T. Kong, U. S. Kaluarachchi, V. Taufour, N. H. Jo, G. Drachuck, A. E. Böhmer, S. M. Saunders, A. Sapkota, A. Kreyssig, M. A. Tanatar, R. Prozorov, A. I. Goldman, Fedor F. Balakirev, Alex Gurevich, S. L. Bud'ko, P. C. Canfield Jan 2016

Anisotropic Thermodynamic And Transport Properties Of Single-Crystalline Cakfe4As4, W. R. Meier, T. Kong, U. S. Kaluarachchi, V. Taufour, N. H. Jo, G. Drachuck, A. E. Böhmer, S. M. Saunders, A. Sapkota, A. Kreyssig, M. A. Tanatar, R. Prozorov, A. I. Goldman, Fedor F. Balakirev, Alex Gurevich, S. L. Bud'ko, P. C. Canfield

Physics Faculty Publications

Single-crystalline, single-phase CaKFe4As4 has been grown out of a high-temperature, quaternary melt. Temperature-dependent measurements of x-ray diffraction, anisotropic electrical resistivity, elastoresistivity, thermoelectric power, Hall effect, magnetization, and specific heat, combined with field-dependent measurements of electrical resistivity and field and pressure-dependent measurements of magnetization indicate that CaKFe4As4 is an ordered, stoichiometric, Fe-based superconductor with a superconducting critical temperature, Tc = 35.0 ± 0.2 K. Other than superconductivity, there is no indication of any other phase transition for 1.8K ≤ T ≤ 300 K. All of these thermodynamic and transport data reveal striking similarities to …


Towards A Resolution Of The Proton Form Factor Problem: New Electron And Positron Scattering Data, Clas Collaboration, D. Adikaram, L. B. Weinstein, R. P. Bennett, K. P, Adhikari, M. J. Amaryan, S. Careccia, L. El Fassi, C. E. Hyde, A. Klein, S E. Kuhn, M. Mayer, Z. W. Zhao Jan 2015

Towards A Resolution Of The Proton Form Factor Problem: New Electron And Positron Scattering Data, Clas Collaboration, D. Adikaram, L. B. Weinstein, R. P. Bennett, K. P, Adhikari, M. J. Amaryan, S. Careccia, L. El Fassi, C. E. Hyde, A. Klein, S E. Kuhn, M. Mayer, Z. W. Zhao

Physics Faculty Publications

There is a significant discrepancy between the values of the proton electric form factor, GpE, extracted using unpolarized and polarized electron scattering. Calculations predict that small two-photon exchange (TPE) contributions can significantly affect the extraction of GpEfrom the unpolarized electron-proton cross sections. We determined the TPE contribution by measuring the ratio of positron-proton to electron-proton elastic scattering cross sections using a simultaneous, tertiary electron-positron beam incident on a liquid hydrogen target and detecting the scattered particles in the Jefferson Lab CLAS detector. This novel technique allowed us to cover a wide range in virtual …


Resonant 𝜋⁺𝜸 → 𝜋⁺𝜋⁰ Amplitude From Quantum Chromodynamics, Raúl A. Briceño, Jozef J. Dudek, Robert G. Edwards, Christian J. Shultz, Christopher E. Thomas, David J. Wilson Jan 2015

Resonant 𝜋⁺𝜸 → 𝜋⁺𝜋⁰ Amplitude From Quantum Chromodynamics, Raúl A. Briceño, Jozef J. Dudek, Robert G. Edwards, Christian J. Shultz, Christopher E. Thomas, David J. Wilson

Physics Faculty Publications

We present the first ab initio calculation of a radiative transition of a hadronic resonance within quantum chromodynamics (QCD). We compute the amplitude for 𝜋𝜋→𝜋𝜸, as a function of the energy of the 𝜋𝜋 pair and the virtuality of the photon, in the kinematic regime where 𝜋𝜋 couples strongly to the unstable ρ resonance. This exploratory calculation is performed using a lattice discretization of QCD with quark masses corresponding to mπ ≈ 400  MeV. We obtain a description of the energy dependence of the transition amplitude, constrained at 48 kinematic points, that we can analytically continue …


Narrow-Band Emission In Thomson Sources Operating In The High-Field Regime, Balša Terzić, Kirsten Deitrick, Alicia S. Hofler, Geoffrey A. Krafft Jan 2014

Narrow-Band Emission In Thomson Sources Operating In The High-Field Regime, Balša Terzić, Kirsten Deitrick, Alicia S. Hofler, Geoffrey A. Krafft

Physics Faculty Publications

We present a novel and quite general analysis of the interaction of a high-field chirped laser pulse and a relativistic electron, in which exquisite control of the spectral brilliance of the up-shifted Thomson-scattered photon is shown to be possible. Normally, when Thomson scattering occurs at high field strengths, there is ponderomotive line broadening in the scattered radiation. This effect makes the bandwidth too large for some applications and reduces the spectral brilliance. We show that such broadening can be corrected and eliminated by suitable frequency modulation of the incident laser pulse. Furthermore, we suggest a practical realization of this compensation …


Data Analysis Techniques, Differential Cross Sections, And Spin Density Matrix Elements For The Reaction 𝛾p → Φp, K. P. Adhikari, D. Adikaram, M. J. Amaryan, C. E. Hyde, S. Koirala, S. E. Kuhn, M. Mayer, I. Niculescu, Et Al., The Clas Collaboration Jan 2014

Data Analysis Techniques, Differential Cross Sections, And Spin Density Matrix Elements For The Reaction 𝛾p → Φp, K. P. Adhikari, D. Adikaram, M. J. Amaryan, C. E. Hyde, S. Koirala, S. E. Kuhn, M. Mayer, I. Niculescu, Et Al., The Clas Collaboration

Physics Faculty Publications

High-statistics measurements of differential cross sections and spin density matrix elements for the reaction γp→ϕp have been made using the CLAS detector at Jefferson Lab. We cover center-of-mass energies (√s) from 1.97 to 2.84 GeV, with an extensive coverage in the ϕ production angle. The high statistics of the data sample made it necessary to carefully account for the interplay between the ϕ natural lineshape and effects of the detector resolution, that are found to be comparable in magnitude. We study both the charged- (ϕ→K+K) and neutral- (ϕ→K0SK0L) K→ …


Scalar Wave Scattering By Two-Layer Radial Inhomogeneities, Umaporn Nuntaplook, John Adam Jan 2014

Scalar Wave Scattering By Two-Layer Radial Inhomogeneities, Umaporn Nuntaplook, John Adam

Mathematics & Statistics Faculty Publications

It is shown that the iteration technique gives a better approximation for the problem with long wavelengths.


Beam-Spin Asymmetries From Semi-Inclusive Pion Electroproduction, K. P. Adhikari, M. J. Amaryan, C. Hyde, S. Koirala, S. E. Kuhn, L. B. Weinstein, Et Al., The Clas Collaboration Jan 2014

Beam-Spin Asymmetries From Semi-Inclusive Pion Electroproduction, K. P. Adhikari, M. J. Amaryan, C. Hyde, S. Koirala, S. E. Kuhn, L. B. Weinstein, Et Al., The Clas Collaboration

Physics Faculty Publications

We have measured the moment Asin ɸLU corresponding to the polarized electron beam-spin asymmetry in semi-inclusive deep inelastic scattering. Asin ɸLU is a twist-3 quantity providing information about quark-gluon correlations. Data were taken with the CLAS Spectrometer at Jefferson Lab using a 5.498 GeV longitudinally polarized electron beam and an unpolarized liquid hydrogen target. All three pion channels (π+0 and π-) were measured simultaneously over a large range of kinematics within the virtuality range Q2 ≈ 1.0- 4.5 GeV2. The observable was measured with better than 1% statistical …


Publisher’S Note: Data Analysis Techniques, Differential Cross Sections, And Spin Density Matrix Elements For The Reaction 𝛾p -> Φp (Phys. Rev. C. Vol 89, 055208, 2014), K. P. Adhikari, D. Adikaram, M. J. Amaryan, C. E. Hyde, A. Klein, S. Koirala, S. E. Kuhn, M. Mayer, I. Niculescu, J. Zhang, Et Al., The Clas Collaboration Jan 2014

Publisher’S Note: Data Analysis Techniques, Differential Cross Sections, And Spin Density Matrix Elements For The Reaction 𝛾p -> Φp (Phys. Rev. C. Vol 89, 055208, 2014), K. P. Adhikari, D. Adikaram, M. J. Amaryan, C. E. Hyde, A. Klein, S. Koirala, S. E. Kuhn, M. Mayer, I. Niculescu, J. Zhang, Et Al., The Clas Collaboration

Physics Faculty Publications

No abstract provided.


Photon Impact Factor And 𝑘T Factorization For Dis In The Next-To-Leading Order, Ian Balitsky, Giovanni A. Chirilli Jan 2013

Photon Impact Factor And 𝑘T Factorization For Dis In The Next-To-Leading Order, Ian Balitsky, Giovanni A. Chirilli

Physics Faculty Publications

The photon impact factor for the Balitsky-Fadin-Kuraev-Lipatov pomeron is calculated in the next-to-leading order approximation using the operator expansion in Wilson lines. The result is represented as a next-to-leading order 𝑘T-factorization formula for the structure functions of small-𝓍 deep inelastic scattering.


Coherent Photoproduction Of Π+ From 3He, K. P. Adhikari, C. E. Hyde, A. Klein, S. E. Kuhn, M. Mayer, F. Sabatié, L. B. Weinstein, Et Al., The Clas Collaboration Jan 2011

Coherent Photoproduction Of Π+ From 3He, K. P. Adhikari, C. E. Hyde, A. Klein, S. E. Kuhn, M. Mayer, F. Sabatié, L. B. Weinstein, Et Al., The Clas Collaboration

Physics Faculty Publications

We have measured the differential cross section for the 𝛾 3He → π+t reaction. This reaction was studied using the Continuous Electron Beam Accelerator Facility (CEBAF) Large Acceptance Spectrometer (CLAS) at Jefferson Lab. Real photons produced with the Hall-B bremsstrahlung tagging system in the energy range from 0.50 to 1.55 GeV were incident on a cryogenic liquid 3He target. The differential cross sections for the 𝛾 3He → π+t reaction were measured as a function of photon-beam energy and pion-scattering angle. Theoretical predictions to date cannot explain the large cross sections except at …


Precise Measurement Of The Neutron Magnetic Form Factor Gnm In The Few-Gev² Region, Clas Collaboration, J. Lachniet, H. Bagdasaryan, S. Bültmann, N. Kalantarians, G. E. Dodge, T. A. Forest, G. Gavalian, C. E. Hyde-Wright, A. Klien, S. E. Kuhn, M. R. Niroula, R. A. Niyazov, L. M. Qin, L. B. Weinstein, J. Zhang Jan 2009

Precise Measurement Of The Neutron Magnetic Form Factor Gnm In The Few-Gev² Region, Clas Collaboration, J. Lachniet, H. Bagdasaryan, S. Bültmann, N. Kalantarians, G. E. Dodge, T. A. Forest, G. Gavalian, C. E. Hyde-Wright, A. Klien, S. E. Kuhn, M. R. Niroula, R. A. Niyazov, L. M. Qin, L. B. Weinstein, J. Zhang

Physics Faculty Publications

The neutron elastic magnetic form factor was extracted from quasielastic electron scattering on deuterium over the range Q2 = 1.0–4.8  GeV2 with the CLAS detector at Jefferson Lab. High precision was achieved with a ratio technique and a simultaneous in situ calibration of the neutron detection efficiency. Neutrons were detected with electromagnetic calorimeters and time-of-flight scintillators at two beam energies. The dipole parametrization gives a good description of the data


Electroproduction Of P Π⁺Π⁻ Off Protons At 0.2 < Q² < 0.6 Gev² And 1.3 < W < 1.57 Gev With The Clas Detector, M. J. Amaryan, H. Baghdasaryan, M. Bektasoglu, S. Bültmann, S. L. Careccia, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde, W. Kim, A. Klein, F. J. Klein, A. Klimenko, S. E. Kuhn, S. Tkachenko, L. B. Weinstein, Et Al., Clas Collaboration Jan 2009

Electroproduction Of P Π⁺Π⁻ Off Protons At 0.2 < Q² < 0.6 Gev² And 1.3 < W < 1.57 Gev With The Clas Detector, M. J. Amaryan, H. Baghdasaryan, M. Bektasoglu, S. Bültmann, S. L. Careccia, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde, W. Kim, A. Klein, F. J. Klein, A. Klimenko, S. E. Kuhn, S. Tkachenko, L. B. Weinstein, Et Al., Clas Collaboration

Physics Faculty Publications

This paper reports on the most comprehensive data set obtained on differential and fully integrated cross sections for the process ep → e'pπ+π-. The data were collected with the CLAS detector at Jefferson Laboratory. Measurements were carried out in the as yet unexplored kinematic region of photon virtuality 0.2 < Q2 < 0.6 GeV2 and invariant mass of the final hadron system W from 1.3 to 1.57 GeV. For the first time, nine independent one-fold differential cross sections were determined in each bin of W and Q2 covered by the measurements. A phenomenological analysis of the data allowed …


Conformal Kernel For The Next-To-Leading-Order Bfkl Equation In 𝒩 = 4 Super Yang-Mills Theory, Ian Balitsky, Giovanni A. Chirilli Jan 2009

Conformal Kernel For The Next-To-Leading-Order Bfkl Equation In 𝒩 = 4 Super Yang-Mills Theory, Ian Balitsky, Giovanni A. Chirilli

Physics Faculty Publications

Using the requirement of Möbius invariance of 𝒩 = 4 super Yang-Mills amplitudes in the Regge limit, we restore the explicit form of the conformal next-to-leading-order Balitsky-Fadin-Kuraev-Lipatov (BFKL) kernel out of the eigenvalues known from the forward next-to-leading-order BFKL result.


Cross Sections And Beam Asymmetries For E ⃗ P → Enπ+ In The Nucleon Resonance Region For 1.7 ⩽ Q2 ⩽ 4.5 Gev2, M. J. Amaryan, H. Bagdasaryan, S. Bültmann, K. V. Dharmawardane, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, N. Kalantarians, A. Klein, A. V. Klimenko, S. E. Kuhn, J. Lachniet, R. A. Niyazov, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Zhang, Et Al., The Clas Collaboration Jan 2008

Cross Sections And Beam Asymmetries For E ⃗ P → Enπ+ In The Nucleon Resonance Region For 1.7 ⩽ Q2 ⩽ 4.5 Gev2, M. J. Amaryan, H. Bagdasaryan, S. Bültmann, K. V. Dharmawardane, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, N. Kalantarians, A. Klein, A. V. Klimenko, S. E. Kuhn, J. Lachniet, R. A. Niyazov, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Zhang, Et Al., The Clas Collaboration

Physics Faculty Publications

The exclusive electroproduction process e ⃗ p → e'nπ+ was measured in the range of the photon virtuality Q2 =1.7-4.5 GeV2, and the invariant mass range for the n π+ system of W=1.15-1.7 GeV using the CEBAF Large Acceptance Spectrometer. For the first time, these kinematics are probed in exclusive π+ production from protons with nearly full coverage in the azimuthal and polar angles of the nπ+ center-of-mass system. The nπ+ channel has particular sensitivity to the isospin 1/2 excited nucleon states, and together with the pπ0 final state will serve …


Cascade Production In The Reactions 𝛾p → K⁺ K⁺(X) And 𝛾p → K⁺K⁺ Π⁻⁻(X), M. J. Amaryan, H. Bagdasaryan, S. Bültmann, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, N. Kalantarians, A. Klein, S. E. Kuhn, M. R. Niroula, S. Tkachenko, L. B. Weinstein, J. Zhang, Et Al., Clas Collaboration Jan 2007

Cascade Production In The Reactions 𝛾p → K⁺ K⁺(X) And 𝛾p → K⁺K⁺ Π⁻⁻(X), M. J. Amaryan, H. Bagdasaryan, S. Bültmann, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, N. Kalantarians, A. Klein, S. E. Kuhn, M. R. Niroula, S. Tkachenko, L. B. Weinstein, J. Zhang, Et Al., Clas Collaboration

Physics Faculty Publications

Photoproduction of the cascade resonances has been investigated in the reactions γp → K + K +(X) and γp → K + K + π −(X). The mass splitting of the ground state (Ξ0) doublet is measured to be 5.4 ± 1.8 MeV/c2, consistent with existing measurements. The differential (total) cross sections for the Ξ have been determined for photon beam energies from 2.75 to 3.85 (4.75) GeV and are consistent with a production mechanism of Y∗→K+Ξ through a t-channel process. The reaction γp→K+K+π−[Ξ0] has also been investigated to …


Cross Sections For The 𝛾p -> K*⁰ Σ⁺ Reaction At E𝛾 = 1.7-3.0 Gev, M. Amarian, H. Bagdasaryan, S. Bültmann, S. L. Careccia, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, A. Klein, A. V. Klimenko, S. E. Kuhn, M. R. Niroula, S. Tkachenko, L. B. Weinstein, J. Zhang, Et Al., The Clas Collaboration Jan 2007

Cross Sections For The 𝛾p -> K*⁰ Σ⁺ Reaction At E𝛾 = 1.7-3.0 Gev, M. Amarian, H. Bagdasaryan, S. Bültmann, S. L. Careccia, G. E. Dodge, G. Gavalian, N. Guler, C. E. Hyde-Wright, A. Klein, A. V. Klimenko, S. E. Kuhn, M. R. Niroula, S. Tkachenko, L. B. Weinstein, J. Zhang, Et Al., The Clas Collaboration

Physics Faculty Publications

Differential cross sections for the reaction 𝛾p→ K*0Σ+ are presented in the photon energy range of 1.7 to 3.0 GeV. The K*0 was detected by its decay products, K+π, in the Continuous Electron Beam Accelerator Facility's large acceptance spectrometer (CLAS) detector at the Thomas Jefferson National Accelerator Facility. These data are the first K*0 photoproduction cross sections ever published over a broad range of angles. Comparison with a theoretical model based on the vector and tensor K-quark couplings shows good agreement with the data, except at forward angles, suggesting that …


Erratum: Cross Sections For The 𝛾p -> K*⁰ Σ⁺ Reaction At E𝛾 = 1.7-3.0 Gev (Physical Review C. 75, 042201), M. Amarian, H. Bagdasaryan, S. Bültmann, G. E. Dodge, G. Gavalian, C. E. Hyde-Wright, A. Klein, S. E. Kuhn, F. Sabatié, L. B. Weinstein, Et. Al., The Clas Collaboration Jan 2007

Erratum: Cross Sections For The 𝛾p -> K*⁰ Σ⁺ Reaction At E𝛾 = 1.7-3.0 Gev (Physical Review C. 75, 042201), M. Amarian, H. Bagdasaryan, S. Bültmann, G. E. Dodge, G. Gavalian, C. E. Hyde-Wright, A. Klein, S. E. Kuhn, F. Sabatié, L. B. Weinstein, Et. Al., The Clas Collaboration

Physics Faculty Publications

No abstract provided.


Experimental Study Of Exclusive ²H(E,E'P)N Reaction Mechanisms At High Q², S. E. Kuhn, M. J. Amaryan, H. Bagdasaryan, M. Bektasoglu, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, N. Guler, C. E. Hyde-Wright, H. G. Juengst, N. Kalantarians, A. Klein, M. R. Niroula, R. A. Niyazov, S. Tkachenko, L. B. Weinstein, J. Zhang, Et. Al., Clas Collaboration Jan 2007

Experimental Study Of Exclusive ²H(E,E'P)N Reaction Mechanisms At High Q², S. E. Kuhn, M. J. Amaryan, H. Bagdasaryan, M. Bektasoglu, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, N. Guler, C. E. Hyde-Wright, H. G. Juengst, N. Kalantarians, A. Klein, M. R. Niroula, R. A. Niyazov, S. Tkachenko, L. B. Weinstein, J. Zhang, Et. Al., Clas Collaboration

Physics Faculty Publications

The reaction 2H(e,e(')p)n has been studied with full kinematic coverage for photon virtuality 1.75 < Q2< 5.5 GeV2. Comparisons of experimental data with theory indicate that for very low values of neutron recoil momentum (pn< 100 MeV/c) the neutron is primarily a spectator and the reaction can be described by the plane-wave impulse approximation. For 100 < pn< 750 MeV/c, proton-neutron rescattering dominates the cross section, while Delta production followed by the NΔ → NN transition is the primary contribution at higher momenta.


A Temporal Approximate Deconvolution Model For Large-Eddy Simulation, C. D. Pruett, B. C. Thomas, C. E. Grosch, T. B. Gatski Feb 2006

A Temporal Approximate Deconvolution Model For Large-Eddy Simulation, C. D. Pruett, B. C. Thomas, C. E. Grosch, T. B. Gatski

CCPO Publications

A temporal approximate deconvolution model (TADM) is developed for large-eddy simulation and is demonstrated for plane-channel flow at Re-tau=590. The TADM combines explicit causal time-domain filtering with linear deconvolution (defiltering) to approximate unfiltered fields and residual stress to arbitrarily high order. The TADM methodology appears to lead to a robust family of residual-stress models that should provide a viable alternative to conventional (spatial) filtering for applications in which spatial filtering is problematic, e.g., for problems requiring unstructured or highly stretched grids. (c) 2006 American Institute of Physics.


Differential Cross Sections For 𝛾 + P → K⁺ + Y For Λ And Σ⁰ Hyperons, H. Bagdasaryan, M. Bektasoglu, S. L. Careccia, S. Bültmann, G. E. Dodge, N. Guler, C. E. Hyde-Wright, H. G. Juengst, A. V. Klimenko, S. E. Kuhn, S. Tkachenko, L. B. Weinstein, J. Zhang, Et Al., Clas Collaboration Jan 2006

Differential Cross Sections For 𝛾 + P → K⁺ + Y For Λ And Σ⁰ Hyperons, H. Bagdasaryan, M. Bektasoglu, S. L. Careccia, S. Bültmann, G. E. Dodge, N. Guler, C. E. Hyde-Wright, H. G. Juengst, A. V. Klimenko, S. E. Kuhn, S. Tkachenko, L. B. Weinstein, J. Zhang, Et Al., Clas Collaboration

Physics Faculty Publications

High-statistics cross sections for the reactions 𝛾 + p → K⁺ + Λ and 𝛾 + p → K⁺ + Σ⁰ have been measured using CLAS at Jefferson Lab for center-of-mass energies W between 1.6 and 2.53 GeV, and for -0.85 < cos θ Kc.m. < +0.95. In the K⁺ + Λ channel we confirm a resonance-like structure near W=1.9 GeV at backward kaon angles. The position and width of this structure change with angle, indicating that more than one resonance is likely playing a role. The K⁺ + Λ channel at forward angles and all energies is well described by a t-channel scaling characteristic of Regge exchange, whereas the same scaling applied to the K⁺ + Σ⁰ channel is less successful. Several existing theoretical models are compared to the data, but none provide a good representation of the results.


Electron Scattering From High-Momentum Neutrons In Deuterium, A.V. Klimenko, S. E. Kuhn, H. Bagdasaryan, S. Bültmann, S. L. Careccia, K. V. Dharmawardane, Gail Dodge, G. Gavalian, N. Guler, C.E. Hyde-Wright, A. Klein, R. A. Niyazov, S. Tkachenko, L. B. Weinstein, Et Al., Clas Collaboration Jan 2006

Electron Scattering From High-Momentum Neutrons In Deuterium, A.V. Klimenko, S. E. Kuhn, H. Bagdasaryan, S. Bültmann, S. L. Careccia, K. V. Dharmawardane, Gail Dodge, G. Gavalian, N. Guler, C.E. Hyde-Wright, A. Klein, R. A. Niyazov, S. Tkachenko, L. B. Weinstein, Et Al., Clas Collaboration

Physics Faculty Publications

We report results from an experiment measuring the semiinclusive reaction 2H(e,e′ps) in which the proton ps is moving at a large angle relative to the momentum transfer. If we assume that the proton was a spectator to the reaction taking place on the neutron in deuterium, the initial state of that neutron can be inferred. This method, known as spectator tagging, can be used to study electron scattering from high-momentum (off-shell) neutrons in deuterium. The data were taken with a 5.765 GeV electron beam on a deuterium target in Jefferson Laboratory's Hall B, using the CEBAF …


Η’ Photoproduction On The Proton For Photon Energies From 1.527 To 2.227 Gev, M. Bektasoglu, S.L. Careccia, K. V. Dharmawardane, G. E. Dodge, C. E. Hyde-Wright, H. G. Juengst, A. Klein, S. E. Kuhn, A. V. Klimenko, L. M. Qin, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Yun, J. Zhang, Et Al., Clas Collaboration Jan 2006

Η’ Photoproduction On The Proton For Photon Energies From 1.527 To 2.227 Gev, M. Bektasoglu, S.L. Careccia, K. V. Dharmawardane, G. E. Dodge, C. E. Hyde-Wright, H. G. Juengst, A. Klein, S. E. Kuhn, A. V. Klimenko, L. M. Qin, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Yun, J. Zhang, Et Al., Clas Collaboration

Physics Faculty Publications

Differential cross sections for the reaction γp→η′p have been measured with the CLAS spectrometer and a tagged photon beam with energies from 1.527 to 2.227 GeV. The results reported here possess much greater accuracy than previous measurements. Analyses of these data suggest for the first time the coupling of the η′N channel to both the S11(1535) and P11(1710) resonances, known to couple strongly to the ηN channel in photoproduction on the proton, and the importance of J=3/2 resonances in the process.


Erratum: Η' Photoproduction On The Proton For Photon Energies From 1.527 To 2.227 Gev (Phys. Rev. Lett. 96, Pg 062001, 2006), H. Bagdasaryan, M. Bektasoglu, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, C. E. Hyde-Wright, A. Klein, S. E. Kuhn, L. M. Qin, F. Sabatié, L. B. Weinstein, Et Al., Clas Collaboration Jan 2006

Erratum: Η' Photoproduction On The Proton For Photon Energies From 1.527 To 2.227 Gev (Phys. Rev. Lett. 96, Pg 062001, 2006), H. Bagdasaryan, M. Bektasoglu, S. L. Careccia, K. V. Dharmawardane, G. E. Dodge, C. E. Hyde-Wright, A. Klein, S. E. Kuhn, L. M. Qin, F. Sabatié, L. B. Weinstein, Et Al., Clas Collaboration

Physics Faculty Publications

No abstract provided.


Beam-Helicity Asymmetries In Double-Charged-Pion Photoproduction On The Proton, H. Bagdasaryan, M. Bektasoglu, S. Bültmann, Gail Dodge, N. Guler, C. E. Hyde-Wright, H. G. Juengst, A. Klein, S. E. Kuhn, L. M. Qin, W. Roberts, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Yun, J. Zhang, Et Al., Clas Collaboration Jan 2005

Beam-Helicity Asymmetries In Double-Charged-Pion Photoproduction On The Proton, H. Bagdasaryan, M. Bektasoglu, S. Bültmann, Gail Dodge, N. Guler, C. E. Hyde-Wright, H. G. Juengst, A. Klein, S. E. Kuhn, L. M. Qin, W. Roberts, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Yun, J. Zhang, Et Al., Clas Collaboration

Physics Faculty Publications

Beam-helicity asymmetries for the two-pion-photoproduction reaction 𝛾⃗p → p π+π- have been studied for the first time in the resonance region for center-of-mass energies between 1.35 and 2.30 GeV. The experiment was performed at Jefferson Lab with the CEBAF Large Acceptance Spectrometer using circularly polarized tagged photons incident on an unpolarized hydrogen target. Beam-helicity-dependent angular distributions of the final-state particles were measured. The large cross-section asymmetries exhibit strong sensitivity to the kinematics and dynamics of the reaction. The data are compared with the results of various phenomenological model calculations, and show that these models currently do not …


High-Energy Effective Action From Scattering Of Qcd Shock Waves, Ian Balitsky Jan 2005

High-Energy Effective Action From Scattering Of Qcd Shock Waves, Ian Balitsky

Physics Faculty Publications

At high energies, the relevant degrees of freedom are Wilson lines—infinite gauge links ordered along straight lines collinear to the velocities of colliding particles. The effective action for these Wilson lines is determined by the scattering of QCD shock waves. I develop the symmetric expansion of the effective action in powers of strength of one of the shock waves and calculate the leading term of the series. The corresponding first-order effective action, symmetric with respect to projectile and target, includes both up and down fan diagrams and pomeron loops.


Exclusive Photoproduction Of The Cascade Ξ Hyperons, H. Bagdasaryan, M. Bektasoglu, K. V. Dharmawardane, G. E. Dodge, T. A. Forest, G. Gavalian, N. Guler, C. E. Hyde-Wright, A. V. Klimenko, S. E. Kuhn, L. M. Qin, L. B. Weinstein, J. Yun, Et Al., Clas Collaboration Jan 2005

Exclusive Photoproduction Of The Cascade Ξ Hyperons, H. Bagdasaryan, M. Bektasoglu, K. V. Dharmawardane, G. E. Dodge, T. A. Forest, G. Gavalian, N. Guler, C. E. Hyde-Wright, A. V. Klimenko, S. E. Kuhn, L. M. Qin, L. B. Weinstein, J. Yun, Et Al., Clas Collaboration

Physics Faculty Publications

We report on the first measurement of exclusive Ξ-(1321) hyperon photoproduction in 𝛾p → K+K+Ξ- for 3.2 < E𝛾 < 3.9 GeV. The final state is identified by the missing mass in p(𝛾,K+K+)X measured with the CLAS detector at Jefferson Laboratory. We have detected a significant number of the ground state Ξ-(1321)1/2+ and have estimated the total cross section for its production. We also have strong evidence for the first excited state Ξ-(1530)3/2+. Photoproduction provides a copious source of Ξ's. We discuss the possibilities of a search for the recently proposed Ξ5- and Ξ5+ …


Complete Measurement Of Three-Body Photodisintegration Of 3He For Photon Energies Between 0.35 And 1.55 Gev, H. Bagdasaryan, M. Bektasoglu, K. V. Dharmawardane, G. E. Dodge, T. A. Forest, G. Gavalian, N. Guler, C. E. Hyde-Wright, A. Klein, S. E. Kuhn, L. M. Qin, S. Stepanyan, L. B. Weinstein, J. Yun, Et Al., The Clas Collaboration Jan 2004

Complete Measurement Of Three-Body Photodisintegration Of 3He For Photon Energies Between 0.35 And 1.55 Gev, H. Bagdasaryan, M. Bektasoglu, K. V. Dharmawardane, G. E. Dodge, T. A. Forest, G. Gavalian, N. Guler, C. E. Hyde-Wright, A. Klein, S. E. Kuhn, L. M. Qin, S. Stepanyan, L. B. Weinstein, J. Yun, Et Al., The Clas Collaboration

Physics Faculty Publications

The three-body photodisintegration of 3He has been measured with the CLAS detector at Jefferson Lab, using tagged photons of energies between 0.35 GeV and 1.55 GeV. The large acceptance of the spectrometer allowed us for the first time to cover a wide momentum and angular range for the two outgoing protons. Three kinematic regions dominated by either two- or three-body contributions have been distinguished and analyzed. The measured cross sections have been compared with results of a theoretical model, which, in certain kinematic ranges, have been found to be in reasonable agreement with the data.