Photoproduction at collider energies: from RHIC and HERA to the LHC (2007)
Baltz, A, Baur, G, Brodsky, S J, D'Enterria, D G, Dreyer, U, Engel, R, ...
We present the mini-proceedings of the workshop on ``Photoproduction at collider energies: from RHIC and HERA to the LHC'' held at the European Centre for Theoretical Studies in Nuclear Physics and...
Photoproduction at collider energies: from RHIC and HERA to the LHC (2007)
Baltz, A., Baur, G., Brodsky, S. J., D'Enterria, David, Dreyer, U., Engel, R., ...
We present the mini-proceedings of the workshop on ``Photoproduction at collider energies: from RHIC and HERA to the LHC'' held at the European Centre for Theoretical Studies in Nuclear Physics and...
Brodsky, S. J., Chakrabarti, D., Harindranath, A., Mukherjee, A., Vary, J. P.
The Fourier transform of the deeply virtual Compton scattering amplitude (DVCS) with respect to the skewness parameter \zeta= Q^2/ 2 p.q can be used to provide an image of the target hadron in the...
Evidence for the Absence of Gluon Orbital Angular Momentum in the Nucleon (2006)
The Sivers mechanism for the single-spin asymmetry in unpolarized lepton scattering from a transversely polarized nucleon is driven by the orbital angular momentum carried by its quark and gluon...
Hadron Optics: Diffraction Patterns in Deeply Virtual Compton Scattering (2006)
Brodsky, S. J., Chakrabarti, D., Harindranath, A., Mukherjee, A., Vary, J. P.
We show that the Fourier transform of the Deeply Virtual Compton Scattering (DVCS) amplitude with respect to the skewness variable $\zeta$ at fixed invariant momentum transfer squared $t$ provides a...
Brodsky, S. J., Gardner, S., Hwang, D. S.
We consider the electric dipole form factor, F_3(q^2), as well as the Dirac and Pauli form factors, F_1(q^2) and F_2(q^2), of the nucleon in the light-front formalism. We derive an exact formula for...
Scaling properties of high p_T inclusive hadron production (2005)
Brodsky, S. J., Pirner, H. J., Raufeisen, J.
We analyze the scaling properties of inclusive hadron production in proton-proton and in heavy ion collisions from fixed target to collider energies. At large transverse momentum p_T, the invariant...
Hadron Spectroscopy and Wavefunctions in QCD and the AdS/CFT Correspondence (2005)
Brodsky, S. J., De Teramond, G. F.
The AdS/CFT correspondence has led to important insights into the properties of quantum chromodynamics even though QCD is a broken conformal theory. A holographic model based on a truncated AdS space...
Novel Aspects of Hard Diffraction in QCD (2005)
Initial- and final-state interactions from gluon-exchange, normally neglected in the parton model have a profound effect in QCD hard-scattering reactions, leading to leading-twist single-spin...
Two-boson truncation of Pauli-Villars-regulated Yukawa theory (2005)
Brodsky, S. J., Hiller, J. R., McCartor, G.
We apply light-front quantization, Pauli-Villars regularization, and numerical techniques to the nonperturbative solution of the dressed-fermion problem in Yukawa theory in 3+1 dimensions. The...
In these lectures, I survey a number of applications of light-front methods to hadron and nuclear physics phenomenology and dynamics, Light-front Fock-state wavefunctions provide a frame-independent...
Testing Quantum Chromodynamics with Antiprotons (2004)
The antiproton storage ring HESR to be constructed at GSI will open up a new range of perturbative and nonperturbative tests of QCD in exclusive and inclusive reactions. I discuss 21 tests of QCD...
New Results in Light-Front Phenomenology (2004)
The light-front quantization of gauge theories such as QCD in light-cone gauge provides a frame-independent wavefunction representation of relativistic bound states, simple forms for current matrix...
Novel QCD Aspects of Hard Diffraction, Antishadowing, and Single-Spin Asymmetries (2004)
It is usually assumed -- following the parton model -- that the leading-twist structure functions measured in deep inelastic lepton-proton scattering are simply the probability distributions for...
Novel Aspects of QCD in Leptoproduction (2004)
I review several topics in electroproduction which test fundamental aspects of QCD. These include the role of final-state interactions in producing diffractive leptoproduction processes, the...
Finite-temperature field theory on the light front (2004)
The formulation of statistical physics using light-front quantization, instead of conventional equal-time boundary conditions, has important advantages for describing relativistic statistical...
Hard diffraction from parton rescattering in QCD (2004)
Brodsky, S. J., Enberg, R., Hoyer, P., Ingelman, G.
We analyze the QCD dynamics of diffractive deep inelastic scattering. The presence of a rapidity gap between the target and diffractive system requires that the target remnant emerges in a color...
Statistical Physics and Light-Front Quantization (2004)
Light-front quantization has important advantages for describing relativistic statistical systems, particularly systems for which boost invariance is essential, such as the fireball created in a...
Constraints on proton structure from precision atomic physics measurements (2004)
Brodsky, S. J., Carlson, C. E., Hiller, J. R., Hwang, D. S.
Ground-state hyperfine splittings in hydrogen and muonium are very well measured. Their difference, after correcting for magnetic moment and reduced mass effects, is due solely to proton...
A nonperturbative calculation of the electron's magnetic moment (2004)
Brodsky, S. J., Franke, V. A., Hiller, J. R., McCartor, G., Paston, S. A., Prokhvatilov, E. V.
In principle, the complete spectrum and bound-state wave functions of a quantum field theory can be determined by finding the eigenvalues and eigensolutions of its light-cone Hamiltonian. One of the...
High Energy Photon-Photon Collisions at a Linear Collider (2004)
High intensity back-scattered laser beams will allow the efficient conversion of a substantial fraction of the incident lepton energy into high energy photons, thus significantly extending the...
Chen, Y. C., Afanasev, A., Brodsky, S. J., Carlson, C. E., Vanderhaeghen, M.
We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer through the scattering off a parton in the proton. We relate the process on the...
QCD Physics Opportunities in Low-Energy Electron-Positron Annihilation (2003)
I survey a number of interesting tests of quantum chromodynamics at the amplitude level which can be carried out in electron-positron annihilation and in photon-photon collisions at low energy,...
Brodsky, S. J., Hiller, J. R., Hwang, D. S., Karmanov, V. A.
We study the analytic structure of light-front wave functions (LFWFs) and its consequences for hadron form factors using an explicitly Lorentz-invariant formulation of the front form. The normal to...
Light-Front Quantization and QCD Phenomena (2003)
The light-front quantization of QCD provides an alternative to lattice gauge theory for computing the mass spectrum, scattering amplitudes, and other physical properties of hadrons directly in...
The effective QCD charge extracted from $\tau$ decay is remarkably constant at small momenta, implying the near-conformal behavior of hadronic interactions at small momentum transfer. The...
Light-Front Hadron Dynamics and AdS/CFT Correspondence (2003)
Brodsky, S. J., De Teramond, G. F.
A remarkable consequence of the AdS/CFT correspondence is the nonperturbative derivation of dimensional counting rules for hard scattering processes. Using string/gauge duality we derive the QCD...
Single-Spin Polarization Effects and the Determination of Timelike Proton Form Factors (2003)
Brodsky, S. J., Carlson, C. E., Hiller, J. R., Hwang, D. S.
We show that measurements of the proton's polarization in electron-positron annihilation to a proton-antiproton pair $e^+ e^- \to p \bar p$ strongly discriminate between the analytic forms of models...
Hard probes in heavy ion collisions at the LHC: PDFs, shadowing and $pA$ collisions (2003)
Accardi, A., Armesto, N., Botje, M., Brodsky, S. J., Cole, B., Eskola, K. J., ...
This manuscript is the outcome of the subgroup ``PDFs, shadowing and $pA$ collisions'' from the CERN workshop ``Hard Probes in Heavy Ion Collisions at the LHC''. In addition to the experimental...
Hard Photodisintegration of a Proton Pair in 3He (2003)
Brodsky, S. J., Frankfurt, L., Gilman, R., Hiller, J. R., Miller, G. A., Piasetzky, E., ...
Hard photodisintegration of the deuteron has been extensively studied in order to understand the dynamics of the transition from hadronic to quark-gluon descriptions of the strong interaction. In...
Light-Front Quantization of Gauge Theories (2003)
Light-front wavefunctions provide a frame-independent representation of hadrons in terms of their physical quark and gluon degrees of freedom. The light-front Hamiltonian formalism provides new...
Spontaneously Broken Chiral Symmetry and Hard QCD Phenomena (2002)
Amarian, M. J., Braun, V. M., Brodsky, S. J., Collins, J., Diehl, M., Ecker, G., ...
These are the mini-proceedings of the workshop ``Spontaneously Broken Chiral Symmetry and Hard QCD Phenomena" held at the Physikzentrum Bad Honnef from July 15 to 19, 2002. Every author presents a...
Brodsky, S. J., Hiller, J. R., McCartor, G.
We obtain analytic, nonperturbative, approximate solutions of Yukawa theory in the one-fermion sector using light-front quantization. The theory is regulated in the ultraviolet by the introduction of...
High-Energy QCD Asymptotics of Photon-Photon Collisions (2002)
Brodsky, S J, Fadin, V S, Kim, V T, Lipatov, L N, Pivovarov, G B
The high-energy behaviour of the total cross section for highly virtual photons, as predicted by the BFKL equation at next-to-leading order (NLO) in QCD, is discussed. The NLO BFKL predictions,...
High-Energy QCD Asymptotics of Photon-Photon Collisions (2002)
Brodsky, S. J., Fadin, V. S., Kim, V. T., Lipatov, L. N., Pivovarov, G. B.
The high-energy behaviour of the total cross section for highly virtual photons, as predicted by the BFKL equation at next-to-leading order (NLO) in QCD, is discussed. The NLO BFKL predictions,...
High-energy asymptotics of Photon-photon collisions in QCD (2001)
Brodsky, S J, Fadin, V S, Kim, V T, Lipatov, L N, Pivovarov, G B
The high-energy behaviour of the total cross section for highly virtual photons, as predicted by the BFKL equation at next-to-leading order (NLO) in QCD, is presented. The NLO BFKL predictions,...
Perspectives and Challenges for QCD Phenomenology (2001)
A fundamental understanding of quantum chromodynamics, particularly at the amplitude level, is essential for progress in high energy physics. For example, the measurement and interpretation of the...
Evading the CKM Hierarchy: Intrinsic Charm in B Decays (2001)
We show that the presence of intrinsic charm in the hadrons' light-cone wave functions, even at a few percent level, provides new, competitive decay mechanisms for B decays which are nominally...
Exact solutions to Pauli-Villars-regulated field theories (2001)
Brodsky, S. J., Hiller, J. R., McCartor, G.
We present a new class of quantum field theories which are exactly solvable. The theories are generated by introducing Pauli-Villars fermionic and bosonic fields with masses degenerate with the...
Brodsky, S. J., Hiller, J. R., McCartor, G.
We apply Pauli-Villars regularization and discretized light-cone quantization to the nonperturbative solution of (3+1)-dimensional Yukawa theory in a single-fermion truncation. Three heavy scalars,...
Two-Photon Processes at Intermediate Energies (2001)
Exclusive hadron production processes in photon-photon collisions provide important tests of QCD at the amplitude level, particularly as measures of hadron distribution amplitudes and skewed parton...
Perturbative QCD and factorization of coherent pion photoproduction on the deuteron (2001)
Brodsky, S. J., Hiller, J. R., Ji, Chueng-Ryong, Miller, G. A.
We analyze the predictions of perturbative QCD for pion photoproduction on the deuteron, gamma D -> pi^0 D, at large momentum transfer using the reduced amplitude formalism. The cluster decomposition...
Photoproduction of charm near threshold (2000)
Brodsky, S. J., Chudakov, E., Hoyer, P., Laget, J. M.
Charm and bottom production near threshold is sensitive to the multi-quark, gluonic, and hidden-color correlations of hadronic and nuclear wavefunctions in QCD since all of the target's constituents...
Jet Asymmetry in High Energy Diffractive Production (2000)
Merino, C., Brodsky, S. J., Rathsman, J.
We propose the asymmetry in the fractional energy of charm versus anticharm jets produced in high energy diffractive photoproduction as a sensitive test of the interference of the Odderon (C = -) and...
Coherent Contributions of Nuclear Mesons to Electroproduction and the HERMES Effect (2000)
Miller, G. A., Brodsky, S. J., Karliner, M.
We show that nuclear sigma, omega, and pi mesons can contribute coherently to enhance the electroproduction cross section on nuclei for longitudinal virtual photons at low Q^2 while depleting the...
Conformal expansions and renormalons (2000)
Brodsky, S J, Gardi, E, Grunberg, G, Rathsman, J
The coefficients in perturbative expansions in gauge theories are factoriallyincreasing, predominantly due to renormalons. This type of factorial increaseis not expected in conformal theories. In QCD...
Hadronic Light-Cone Wavefunctions and the Unification of QCD Bound-State Phenomena (2000)
The light-cone Fock representation encodes the bound-state quark and gluon properties of hadrons, including their helicity and flavor correlations, in terms of universal process-independent and...
QCD Processes at the Amplitude Level (1999)
Some of the most difficult theoretical challenges of QCD occur at the interface of the perturbative and nonperturbative regimes. Exclusive and semi-exclusive processes, the diffractive dissociation...
Perturbative QCD relations inspired by hypothetical tau leptons (1999)
Pelaez, J. R., Brodsky, S. J., Merino, C., Toumbas, N.
We review our recent works on tests of perturbative QCD, inspired by the relation between the hadronic decay of the tau lepton and the e+ e- annihilation into hadrons. First, we present a set of...
Hard Exclusive and Diffractive Processes in QCD (1999)
Exclusive and semi-exclusive processes, the diffractive dissociation of hadrons into jets, and hard diffractive processes such as vector meson leptoproduction provide new testing grounds for QCD and...
Perspectives on EPIC Physics (1999)
An electron-proton/ion polarized beam collider (EPIC) with high luminosity and center-of-mass energy $\sqrt s = 25$ GeV would be a valuable facility for fundamental studies of proton and nuclear...
Measuring the QCD Gell Mann-Low $\Psi$-function (1999)
Brodsky, S. J., Merino, C., Pelaez, J. R.
We present a general method for extracting the Gell Mann-Low logarithmic derivative of an effective charge of an observable directly from data as a mean for empirically verifying the universal terms...
New Tests of Perturbative QCD Inspired by Hypothetical Tau Leptons (1999)
Pelaez, J. R., Brodsky, S. J., Toumbas, N.
Inspired by the relation between the hadronic decay of the tau lepton and the electron-positron annihilation into hadrons, we derive new tests of perturbative QCD. We design a set of commensurate...
Semi-Exclusive Processes: New Probes of Hadron Structure (1998)
Brodsky, S. J., Diehl, M., Hoyer, P., Peigne, S.
We define and study hard ``semi-exclusive'' processes of the form $A+B \to C + Y$ which are characterized by a large momentum transfer between the particles $A$ and $C$ and a large rapidity gap...
Commensurate scale relations are perturbative QCD predictions which relate observable to observable at fixed relative scale, such as the ``generalized Crewther relation", which connects the Bjorken...
Testing QCD with Hypothetical Tau Leptons (1998)
Brodsky, S. J., Pelaez, J. R., Toumbas, N.
We construct new tests of perturbative QCD by considering a hypothetical tau lepton of arbitrary mass, which decays hadronically through the electromagnetic current. We can explicitly compute its...
Exact Light-Cone Wavefunction Representation of Matrix Elements of Electroweak Current (1998)
The matrix elements of electroweak currents which occur in exclusive decays of heavy hadrons are evaluated in the nonperturbative light-cone Fock representration. In general, each semileptonic...
The Generalized Crewther Relation in QCD and its Experimental Consequences (1998)
S. J. Brodsky, G. T. Gabadadze, A. L. Kataev, H. J. Lu
We use the BLM scale-fixing prescription to derive a renormalization-scheme invariant relation between the coefficient function for the Bjorken sum rule for polarized deep inelastic scattering and...
Brodsky, S. J., Hiller, J. R., McCartor, G.
We propose a solution to the problem of renormalizing light-cone Hamiltonian theories while maintaining Lorentz invariance and other symmetries. The method uses generalized Pauli--Villars regulators...
High Energy Photon-Photon and Electron-Photon Collisions (1998)
The advent of a next linear $e^\pm e^-$ collider and back-scatterd laser beams will allow the study of a vast array of high energy processes of the Standard Model through the fusion of real and...
Light-Cone Quantized QCD and Novel Hadron Phenomenology (1997)
I review progress made in solving gauge theories such as collinear quantum chromodynamics using light-cone Hamiltonian methods. I also show how the light-cone Fock expansion for hadron wavefunctions...
Exclusive Photon-Photon Processes (1997)
Exclusive $\gamma\gamma \to$ hadron pairs are among the most fundamental processes in QCD, providing a detailed examination of Compton scattering in the crossed channel. In the high momentum transfer...
BFKL Scattering at LEPII and a Next e+ e- Collider (1997)
Brodsky, S. J., Hautmann, F., Soper, D. E.
We discuss virtual photon scattering in the region dominated by BFKL exchange and report results for the cross sections at present and future e+ e- colliders.
The Spin and Flavor Content of Intrinsic Sea Quarks (1997)
The intrinsic quark-antiquark pairs generated by the minimal energy nonperturbative meson-baryon fluctuations in the nucleon sea provide a consistent framework for understanding a number of empirical...
Is J/psi-Nucleon Scattering Dominated by the Gluonic van der Waals Interaction? (1997)
The gluon-exchange contribution to $J/\psi$-nucleon scattering is shown to yield a sizeable scattering length of about -0.25 fm, which is consistent with the sparse available data. Hadronic...
Padé approximants, optimal renormalization scales, and momentum flow in Feynman diagrams (1997)
Brodsky, S J, Ellis, Jonathan Richard, Gardi, E, Karliner, M M, Samuel, Mark A
We show that the Padé Approximant (PA) approach for resummation of perturbative series in QCD provides a systematic method for approximating the flow of momentum in Feynman diagrams. In the...
Virtual photon scattering at high energies as a probe of the short distance pomeron (1997)
Brodsky, S. J., Hautmann, F., Soper, D. E.
Perturbative QCD predicts the behavior of scattering at high energies and fixed (sufficiently large) transferred momenta in terms of the BFKL pomeron (or short distance pomeron). We study the...
Light-Cone Wavefunctions at Small $x$ (1997)
Antonuccio, F, Brodsky, S J, Dalley, S
There exist an infinite number of exact small momentum fraction-$x$ boundary conditions on light-cone wavefunctions of bound states in gauge theory. They are necessary for finite expectation values...
Light-Cone Wavefunctions at Small $x$ (1997)
Antonuccio, F., Brodsky, S. J., Dalley, S.
There exist an infinite number of exact small momentum fraction-$x$ boundary conditions on light-cone wavefunctions of bound states in gauge theory. They are necessary for finite expectation values...
Optimal Renormalization Scale and Scheme for Exclusive Processes (1997)
Brodsky, S. J., Pang, A., Robertson, D. G.
We use the BLM method to fix the renormalization scale of the QCD coupling in exclusive hadronic amplitudes such as the pion form factor and the photon-to-pion transition form factor at large...
Looking for Exotic Multiquark States in Nonleptonic B Decays (1997)
Brodsky, S. J., Navarra, F. S.
Recent data on inclusive B decays into charmonium states taken by the CLEO collaboration suggest that a sizeable fraction of the nonleptonic decays may consist of the $J/\psi \Lambda \overline p$...
Asymmetric Quark/Antiquark Hadronization in e+e- Annihilation (1996)
We point out that the fragmentation of a strange quark into nucleons versus antinucleons is not necessarily identical $D_{p/s}(z,Q^2) \neq D_{\bar p/s}(z,Q^2)$, even though the perturbative...
Novel QCD Effects in the Production and Decay of Quarkonium (1996)
There are many outstanding discrepancies comparing the predictions of perturbative QCD and measurements of the rate of production and decay of heavy quark systems. The problems include the $J/\psi...
The Drell-Yan Process and Factorization in Impact Parameter Space (1996)
Brodsky, S. J., Hebecker, A., Quack, E.
The cross section for Drell-Yan pair production in the limit of small $x$-target is derived in the rest frame of the target hadron. Our calculation is based on the fundamental quantity...
Nonperturbative Renormalization of QED in Light-Cone Quantization (1996)
As a precursor to work on QCD, we study the dressed electron in QED nonperturbatively. The calculational scheme uses an invariant mass cutoff, discretized light-cone quantization, a Tamm--Dancoff...
Light-Cone Quantization and Hadron Structure (1996)
In this talk, I review the use of the light-cone Fock expansion as a tractable and consistent description of relativistic many-body systems and bound states in quantum field theory and as a...
The Quark/Antiquark Asymmetry of the Nucleon Sea (1996)
Although the distributions of sea quarks and antiquarks generated by leading-twist QCD evolution through gluon splitting $g \rightarrow \bar q q$ are necessarily CP symmetric, the distributions of...
The Generalized Crewther Relation in QCD and its Experimental Consequences (1995)
Brodsky, S. J., Gabadadze, G. T., Kataev, A. L., Lu, H. J.
We use the BLM scale-fixing prescription to derive a renormalization-scheme invariant relation between the coefficient function for the Bjorken sum rule for polarized deep inelastic scattering and...
Charmed Hadron Asymmetries in the Intrinsic Charm Coalescence Model (1995)
Fermilab experiment E791, measuring charmed hadron production in $\pi^- A$ interactions at 500 GeV with high statistics, has observed a strong asymmetry between the hadroproduction cross sections for...
Light-Cone Quantization and QCD Phenomenology (1995)
Brodsky, S. J., Robertson, D. G.
In principle, quantum chromodynamics provides a fundamental description of hadronic and nuclear structure and dynamics in terms of their elementary quark and gluon degrees of freedom. In practice,...
Angular Distributions of Massive Quarks and Leptons Close to Threshold (1995)
Brodsky, S. J., Hoang, A. H., Kuhn, J. H., Teubner, T.
Predictions for the angular distribution of massive quarks and leptons are presented, including QCD and QED corrections. Recent results for the fermionic part of the two-loop corrections to the...