Probing Spin Dependent Parton Distributions though Deeply Virtual Processes

TL;DR

This paper explores how generalized parton distributions, especially chiral odd amplitudes, can be studied through angular and polarization observables in deeply virtual meson production, linking QCD structure to measurable quantities.

Contribution

It introduces specific observables that connect chiral odd helicity amplitudes to deeply virtual $$ production, aiding phenomenological extraction of GPDs.

Findings

Identifies observables sensitive to chiral odd GPDs.

Links helicity amplitudes to measurable asymmetries.

Provides a framework for experimental extraction of GPDs.

Abstract

Spin and transverse momentum dependent parton distributions - Generalized Parton Distributions (GPDs) - are at the interface between the QCD structure of the hadrons and observable quantities. The GPDs are linear superpositions within helicity amplitudes. The amplitudes are probed in high energy leptoproduction processes through angular dependent cross sections and polarization asymmetries. Phenomenological extraction of the amplitudes and the distributions is a challenging task. We present observables that connect particularly with the chiral odd quark-nucleon helicity amplitudes for Deeply Virtual $\pi^0$ Production.