From chiral quark models to high-energy processes

TL;DR

This paper uses low-energy chiral quark models to predict soft matrix elements involving pions and photons, demonstrating good agreement with data after QCD evolution to high-energy scales.

Contribution

It applies chiral quark models to compute generalized parton distributions and related quantities, connecting low-energy models with high-energy experimental data.

Findings

Good agreement with experimental and lattice data

QCD evolution is essential for matching scales

Model successfully predicts pion structure functions

Abstract

We show the results of low-energy chiral quark models for soft matrix elements involving pions and photons. Such soft elements, upon convolution with the hard matrix elements, are relevant in various high-energy processes. We focus on quantities related to the generalized parton distributions of the pion: the parton distribution functions, the parton distribution amplitudes, and the generalized form factors. Wherever possible, the model predictions are confronted with the data or lattice simulations, where surprisingly good agreement is achieved. The QCD evolution from the low quark model scale up to the scale of the data is crucial for this agreement.