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Articles 91 - 103 of 103
Full-Text Articles in Physics
Quark-Hadron Duality In Spin Structure Functions G(1)(P) And G(1)(D), P. E. Bosted, K. V. Dharmawardane, G. E. Dodge, T. A. Forest, S. E. Kuhn, Y. Prok, G. Adams, M. Amarian, P. Ambrozewicz, M. Anghinolfi, H. Bagdasaryan, M. Bektasoglu, S. Bültmann, S. L. Careccia, G. Gavalian, N. Guler, C. E. Hyde-Wright, H. G. Juengst, A. Klein, J. Lachniet, R. A. Niyazov, L. M. Qin, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Yun, J. Zhang
Quark-Hadron Duality In Spin Structure Functions G(1)(P) And G(1)(D), P. E. Bosted, K. V. Dharmawardane, G. E. Dodge, T. A. Forest, S. E. Kuhn, Y. Prok, G. Adams, M. Amarian, P. Ambrozewicz, M. Anghinolfi, H. Bagdasaryan, M. Bektasoglu, S. Bültmann, S. L. Careccia, G. Gavalian, N. Guler, C. E. Hyde-Wright, H. G. Juengst, A. Klein, J. Lachniet, R. A. Niyazov, L. M. Qin, F. Sabatié, S. Tkachenko, L. B. Weinstein, J. Yun, J. Zhang
Physics Faculty Publications
New measurements of the spin structure functions of the proton and deuteron g(1)(p)(x,Q2) and g(1)(d)(x,Q2) in the nucleon resonance region are compared with extrapolations of target-mass-corrected next-to-leading-order (NLO) QCD fits to higher energy data. Averaged over the entire resonance region (W <2 >GeV), the data and QCD fits are in good agreement in both magnitude and Q2 dependence for Q2 >1.7 GeV2/c2. This "global" duality appears to result from cancellations among the prominent "local" resonance regions: in particular strong σ …
Quark Contribution To The Small-𝔁 Evolution Of Color Dipole, Ian Balitsky
Quark Contribution To The Small-𝔁 Evolution Of Color Dipole, Ian Balitsky
Physics Faculty Publications
The small-𝔁 deep inelastic scattering in the saturation region is governed by the nonlinear evolution of Wilson-lines operators. In the leading logarithmic approximation it is given by the Balitsky-Kovchegov (BK) equation for the evolution of color dipoles. In the next-to-leading order (NLO) the nonlinear equation gets contributions from quark and gluon loops. In this paper I calculate the quark-loop contribution to small-𝔁 evolution of Wilson lines in the NLO. It turns out that there are no new operators at the one-loop level—just as at the tree level, the high-energy scattering can be described in terms of Wilson lines. In addition, …
High-Energy Effective Action From Scattering Of Qcd Shock Waves, Ian Balitsky
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
Higher Twist Analysis Of The Proton G₁ Structure Function, M. Osipenko, W. Melnitchouk, S. Simula, P. Bosted, V. Burkert, M. E. Christy, K. Griffioen, C. Keppel, S. E. Kuhn
Higher Twist Analysis Of The Proton G₁ Structure Function, M. Osipenko, W. Melnitchouk, S. Simula, P. Bosted, V. Burkert, M. E. Christy, K. Griffioen, C. Keppel, S. E. Kuhn
Physics Faculty Publications
We perform a global analysis of all available spin-dependent proton structure function data, covering a large range of Q2, 1 ⩽ Q2 ⩽ 30 GeV2, and calculate the lowest moment of the g1 structure function as a function of Q2. From the Q2 dependence of the lowest moment we extract matrix elements of twist-4 operators, and determine the color electric and magnetic polarizabilities of the proton to be XE= 0.026 ± 0.015(stat) ± 0.0210.024 (sys) and XB= -0.013 ∓ 0.007(stat) ∓ 0.010 0.012(sys), respectively.
High-Energy Effective Action From Scattering Of Qcd Shock Waves, Ian Balitsky
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.
Inclusive And Exclusive Compton Processes In Quantum Chromodynamics, A. Psaker
Inclusive And Exclusive Compton Processes In Quantum Chromodynamics, A. Psaker
Physics Theses & Dissertations
In our work, we describe two types of Compton processes. As an example of an inclusive process, we consider the high-energy photoproduction of massive muon pairs off the nucleon. We analyze the process in the framework of the QCD parton model, in which the usual parton distributions emerge as a tool to describe the nucleon in terms of quark and gluonic degrees of freedom. To study its exclusive version, a new class of phenomenological functions is required, namely, generalized parton distributions. They can be considered as a generalization of the usual parton distributions measured in deeply inelastic lepton-nucleon scattering. Generalized …
Scattering Of Shock Waves In Qcd, Ian Balitsky
Scattering Of Shock Waves In Qcd, Ian Balitsky
Physics Faculty Publications
The cross section of heavy-ion collisions is represented as a double functional integral with the saddle point being the classical solution of the Yang-Mills equations with boundary conditions/sources in the form of two shock waves corresponding to the two colliding ions. I develop the expansion of this classical solution in powers of the commutator of the Wilson lines describing the colliding particles and calculate the first two terms of the expansion.
Complete Angular Distribution Measurements Of Two-Body Deuteron Photodisintegration Between 0.5 And 3 Gev, H. Bagdasaryan, H. Bektasoglu, G. E. Dodge, T. A. Forest, C. E. Hyde-Wright, A. Klein, A. V. Klimenko, S. E. Kuhn, F. Sabatié, S. Stepanyan, L. B. Weinstein, J. Yun, Et Al., The Clas Collaboration
Complete Angular Distribution Measurements Of Two-Body Deuteron Photodisintegration Between 0.5 And 3 Gev, H. Bagdasaryan, H. Bektasoglu, G. E. Dodge, T. A. Forest, C. E. Hyde-Wright, A. Klein, A. V. Klimenko, S. E. Kuhn, F. Sabatié, S. Stepanyan, L. B. Weinstein, J. Yun, Et Al., The Clas Collaboration
Physics Faculty Publications
Nearly complete angular distributions of the two-body deuteron photodisintegration differential cross section have been measured using the CEBAF Large Acceptance Spectrometer detector and the tagged photon beam at the Thomas Jefferson National Accelerator Facility. The data cover photon energies between 0.5 and 3.0 GeV and center-of-mass proton scattering angles 10°–160°. The data show a persistent forward-backward angle asymmetry over the explored energy range, and are well described by the nonperturbative quark gluon string model.
Generalized Compton Amplitudes In Quantum Chromodynamics, Ignati Grigentch
Generalized Compton Amplitudes In Quantum Chromodynamics, Ignati Grigentch
Physics Theses & Dissertations
In this dissertation we describe results of our studies of generalized Compton amplitudes. We have calculated the one-loop corrections to the amplitude in the coordinate representation in terms of nonlocal string light-ray operators. We have also developed a consistent approach to the problem of constructing the gauge invariant Compton amplitude and obtained an expression for the explicitly gauge invariant amplitude which includes all the generalized target-mass corrections.
Deeply Virtual Compton Scattering At Small X, Ian Balitsky, Elena Kuchina
Deeply Virtual Compton Scattering At Small X, Ian Balitsky, Elena Kuchina
Physics Faculty Publications
We calculate the cross section of deeply virtual Compton scattering at large energies and intermediate momentum transfers.
High Energy Effective Action From Scattering Of Shock Waves In Qcd, Ian Balitsky
High Energy Effective Action From Scattering Of Shock Waves In Qcd, Ian Balitsky
Physics Faculty Publications
The author demonstrates that the amplitude for high-energy scattering can be factorized as a convolution of the contributions due to fast and slow fields. The fast and slow fields interact by means of Wilson-line operators -- infinite gauge factors ordered along the straight line. The resulting factorization formula gives a starting point for a new approach to the effective action for high-energy scattering in QCD.
Virtual Compton Scattering Processes In Quantum Chromodynamics, Igor V. Musatov
Virtual Compton Scattering Processes In Quantum Chromodynamics, Igor V. Musatov
Physics Theses & Dissertations
Applications of perturbative QCD to deeply virtual Compton scattering and hard exclusive meson electroproduction processes require a generalization of usual Parton distributions for the case when long-distance information is accumulated in nonforward matrix elements [special characters omitted] of quark and gluon light-cone operators. We consider different aspects of the investigation of the virtual Compton amplitude in the QCD on two examples: the spin dependent observables in the forward virtual Compton process (measured in the experiments on deep inelastic scattering) and the γγ* transition form factor. Then we discuss in detail evolution equations for non-forward parton distributions [special characters omitted] The …
Factorization And Effective Action For High-Energy Scattering In Qcd, Ian Balitsky
Factorization And Effective Action For High-Energy Scattering In Qcd, Ian Balitsky
Physics Faculty Publications
The author demonstrates that the amplitude of the high-energy scattering can be factorized in a convolution of the contributions due to fast and slow fields. The fast and slow fields interact by means of Wilson-line operators -- infinite gauge factors ordered along the straight line. The resulting factorization formula gives a starting point for a new approach to the effective action for high-energy scattering.