Event Shapes and Power Corrections in ep DIS

TL;DR

This paper analyzes event shape variables in deep-inelastic ep scattering data from HERA, testing perturbative QCD predictions and power corrections across a wide energy range to understand hadronization effects.

Contribution

It applies and tests the concept of power law corrections in perturbative QCD for event shape variables in ep DIS over a broad energy spectrum.

Findings

Power corrections proportional to 1/Q^p effectively describe hadronization effects.

The non-perturbative parameter alpha_{p-1} is systematically investigated.

Strong coupling constant is extracted from the data.

Abstract

Deep-inelastic ep scattering data, taken with the H1 detector at HERA, are used to study the event shape variables thrust, jet broadening, jet mass, C parameter, and two kinds of differential two-jet rates over a large range of ``relevant energy'' Q between 7 GeV and 100 GeV. The Q dependence of the mean values is fit to second order calculations of perturbative QCD applying power law corrections proportional to 1/Q^p to account for hadronization effects. The concept of these power corrections is tested by a systematic investigation in terms of a non-perturbative parameter alpha_{p-1} and the strong coupling constant.