Investigation of Power Corrections to Event Shape Variables measured in Deep-Inelastic Scattering

TL;DR

This paper analyzes how power corrections influence event shape variables in deep-inelastic scattering, comparing experimental data with perturbative QCD calculations and fitting non-perturbative parameters across a wide energy range.

Contribution

It provides a detailed investigation of power corrections in deep-inelastic scattering and introduces a method to fit non-perturbative parameters alongside the strong coupling constant.

Findings

Power corrections improve the agreement between data and QCD predictions.

The fitted non-perturbative parameter alpha_p is consistent across different event shape variables.

The study covers a broad Q range from 7 GeV to 100 GeV.

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 rate. The data cover a large range of the four-momentum transfer Q, which is considered to be the relevant energy scale, between 7 GeV and 100 GeV. The Q dependences of the mean values are compared with second order calculations of perturbative QCD applying power law corrections proportional to 1/Q^p to account for hadronization effects. The concept of power corrections is investigated by fitting simultaneously a non-perturbative parameter alpha_p and the strong coupling constant alpha_s.