On Extraction of Twist-Two Compton Form Factors from DVCS Observables Through Harmonic Analysis

Abstract

We investigate the exercise of locally extracting the real and imaginary parts of the four twist-2 Compton form factors (CFFs) $\{\mathcal{H},\mathcal{E},\tilde{\mathcal{H}},\tilde{\mathcal{E}}\}$ which arise in the deeply virtual Compton scattering (DVCS) process $e+p\to e+p+\gamma$. Neglecting dynamical higher-twist contributions, we find that there are a sufficient number of DVCS observables and degrees of freedom to extract all 8 leading quantities model-independently, exploiting the azimuthal dependence of the absolute cross sections across all possible beam and target polarizations at a common kinematical point in $\{Q,t,x_B,y\}$. As an example, for typical JLab lab-frame kinematics, we simplify the reduced DVCS observables to their dominant terms, providing a sufficient number of equations for local determination of the twist-2 CFFs. We demonstrate the feasibility using harmonic fitting to both cross sections and beam spin asymmetries with both real and pseudo-data.

52 pages, 8 figures, 5 tables

References in corpus (8)

• Electron-Ion Collider in China
• Towards a fitting procedure for deeply virtual Compton scattering at next-to-leading order and beyond
• A fitter code for Deep Virtual Compton Scattering and Generalized Parton Distributions
• Unbiased determination of DVCS Compton Form Factors
• Deep Learning Analysis of Deeply Virtual Exclusive Photoproduction
• Higher-Order Kinematical Effects in Deeply Virtual Compton Scattering
• Twist-three cross-sections in deeply virtual Compton scattering
• Generalized Parton Distributions and Deeply Virtual Compton Scattering

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• Accessing Compton Form Factors at the Electron Ion Collider in China: An Impact study on $\text{Im}\mathcal{E}$
• Unified and optimal frame choice for generalized parton distributions
• New framework for extracting GPDs from exclusive photon electroproduction