PQCD Analysis of Parton-Hadron Duality

TL;DR

This paper extracts the QCD running coupling constant in the infrared region from deep inelastic scattering data at high x, incorporating target mass corrections and resummation effects to improve fit quality.

Contribution

It introduces a method to determine the infrared strong coupling from experimental data, reducing the need for additional higher twist corrections by including resummation effects.

Findings

Infrared strong coupling can be extracted from high-x DIS data.

Resummation effects improve the fit to data without extra power corrections.

The approach provides a new way to probe non-perturbative QCD effects.

Abstract

We propose an extraction of the running coupling constant of QCD in the infrared region from experimental data on deep inelastic inclusive scattering at Bjorken x -> 1. We first attempt a perturbative fit of the data that extends NLO PQCD evolution to large x values and final state invariant mass, W, in the resonance region. We include both target mass corrections and large x resummation effects. These effects are of order O(1/Q^2), and they improve the agreement with the Q^2 dependence of the data. Standard analyses require the presence of additional power corrections, or dynamical higher twists, to achieve a fully quantitative fit. Our analysis, however, is regulated by the value of the strong coupling in the infrared region that enters through large x resummation effects, and that can suppress, or absorb, higher twist effects. Large x data therefore indirectly provide a measurement of this quantity that can be compared to extractions from other observables.