Compton Scattering and Fixed Poles in Parton Field-Theoretic Models

Brodsky, Stanley J.; Close, F. E.; Gunion, John F.

doi:10.1103/physrevd.5.1384

Cited by 116 publications

(110 citation statements)

References 15 publications

Supporting

Mentioning

108

Contrasting

Order By: Relevance

“…On the theoretical side studies in the partonic [127,128] or light-cone [129,130] approach lead to a real term in the transversal part of the (forward) Compton amplitude that in the language of Reggeization was interpreted as a J = 0 fixed pole. Nevertheless, via a subtracted sum rule [131,132,127,128] it is related to the imaginary part of the Compton amplitude. This would imply that there is no separate D-term contribution in the central GPD region.…”

Section: Discussing the Subtraction Constantmentioning

confidence: 99%

Towards a fitting procedure for deeply virtual Compton scattering at next-to-leading order and beyond

2008

View full text Add to dashboard Cite

Combining dispersion and operator product expansion techniques, we derive the conformal partial wave decomposition of the virtual Compton scattering amplitude in terms of complex conformal spin to twist-two accuracy. The perturbation theory predictions for the deeply virtual Compton scattering (DVCS) amplitude are presented in next-to-leading order for both conformal and modified minimal subtraction scheme. Within a conformal subtraction scheme, where we exploit predictive power of conformal symmetry, the radiative corrections are presented up to next-to-nextto-leading order accuracy. Here, because of the trace anomaly, the mixing of conformal moments of generalized parton distributions (GPD) at the three-loop level remains unknown. Within a new proposed parameterization for GPDs, we then study the convergence of perturbation theory and demonstrate that our formalism is suitable for a fitting procedure of DVCS observables.

show abstract

Section: Discussing the Subtraction Constantmentioning

confidence: 99%

Towards a fitting procedure for deeply virtual Compton scattering at next-to-leading order and beyond

2008

View full text Add to dashboard Cite

show abstract

“…It is already apparent that any divergence of S must arise from the q 2 -+ -00 limit. There is good reason to believe that such singularities are fixed [5,14,15,16](i. e., they occur at J=a! (t) where o(t)=0 for all t) and have residues which are polynomial in q2 for amplitudes free of kinematic singularities [5,15].…”

Section: Derivation Of the Schwinger Term Sum Rule From The Bjl Tmentioning

confidence: 99%

“…(3) becomes: gi ALL qOqi(tL(q2, ') + t2(q2, '))= --' + O ~ + qip(S2, ') 90 \ 1 40 (5) where P(q2, v ) is some polynomial in q2 and v , which is to be identified with terms on the right-hand side which do not vanish as q. -im.…”

Section: Derivation Of the Schwinger Term Sum Rule From The Bjl Tmentioning

confidence: 99%

“…Our object is to present a straightforward and systematic analysis of these apparent divergences employing several of the techniques for writing finite sum rules which have been developed over the past few years [4,5,6], and using the Schwinger term sum rule as an example [7]. These techniques and our conclusions are quite general and apply to a wide class of sum rules, some of which we shall enumerate.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

On the finiteness of scaling sum rules

1973

View full text Add to dashboard Cite

The convergence of sum rules relating the matrix elements of local, operators to integrals over deep-inelastic structure functions is studied critically.It is found that the matrix elements may always be written as the q2 --03 limit of finite expressions, regardless of the (Regge) The treatment is readily applicable to other scaling and fixed q2 sum rules needing regulation. A compendium of these is given.-3-

show abstract

“…e p can provide a remarkable window to the QCD structure of hadrons at the amplitude level. The interference of the DVCS amplitude and the coherent Bethe-Heitler amplitude leads to an e asymmetry which is related to the real part of the DVCS amplitude [2]. The imaginary part can also be accessed through various spin asymmetries [3].…”

Section: Introductionmentioning

confidence: 99%

Hadron optics in three-dimensional invariant coordinate space from deeply virtual Compton scattering

et al. 2007

View full text Add to dashboard Cite

The Fourier transform of the deeply virtual Compton scattering amplitude (DVCS) with respect to the skewness parameter Q 2 =2p q can be used to provide an image of the target hadron in the boostinvariant variable , the coordinate conjugate to light-front time t z=c. As an illustration, we construct a consistent covariant model of the DVCS amplitude and its associated generalized parton distributions using the quantum fluctuations of a fermion state at one loop in QED, thus providing a representation of the light-front wave functions (LFWFs) of a lepton in space. A consistent model for hadronic amplitudes can then be obtained by differentiating the light-front wave functions with respect to the bound-state mass. The resulting DVCS helicity amplitudes are evaluated as a function of and the impact parameterb ? , thus providing a light-front image of the target hadron in a frame-independent threedimensional light-front coordinate space. Models for the LFWFs of hadrons in 3 1 dimensions displaying confinement at large distances and conformal symmetry at short distances have been obtained using the AdS/CFT method. We also compute the LFWFs in this model in invariant three-dimensional coordinate space. We find that, in the models studied, the Fourier transform of the DVCS amplitudes exhibit diffraction patterns. The results are analogous to the diffractive scattering of a wave in optics where the distribution in measures the physical size of the scattering center in a one-dimensional system.

show abstract

Compton Scattering and Fixed Poles in Parton Field-Theoretic Models

Cited by 116 publications

References 15 publications

Towards a fitting procedure for deeply virtual Compton scattering at next-to-leading order and beyond

Towards a fitting procedure for deeply virtual Compton scattering at next-to-leading order and beyond

On the finiteness of scaling sum rules

Hadron optics in three-dimensional invariant coordinate space from deeply virtual Compton scattering

Contact Info

Product

Resources

About