Double deeply virtual Compton scattering with positron beams at SoLID

TL;DR

This paper explores the potential of using positron beams at SoLID to measure double deeply virtual Compton scattering, providing new insights into the Generalized Parton Distributions and higher twist effects.

Contribution

It proposes an experimental setup with polarized and unpolarized positron and electron beams at 11 GeV to access GPDs in an unexplored phase space.

Findings

Access to real and imaginary parts of the Compton Form Factor ${\ m\mathcal H}$

Unprecedented phase space coverage for GPDs

Potential to investigate higher twist effects

Abstract

Double Deeply Virtual Compton Scattering (DDVCS) is the only experimental channel for the determination of the dependence of the Generalized Parton Distributions (GPDs) on both the average and the transferred momentum independently. The physics observables of the electron induced di-muon production reaction $\vv{e}^{\pm}p \to e^{\pm}p\mu^+\mu^-$ off unpolarized hydrogen are discussed. Their measurement with the high luminosity and large acceptance SoLID spectrometer at the Thomas Jefferson National Accelerator Facility, using polarized and unpolarized positron and electron beams at 11 GeV is investigated. This experimental configuration is shown to provide unprecedented access to the GPDs with the determination of the real and imaginary parts of the Compton Form Factor ${\mathcal H}$ in an unexplored phase space, and to enable an exploratory investigation of higher twist effects.