QCD Analysis of Polarized Inclusive and Semi-inclusive DIS Data

TL;DR

This paper presents a comprehensive NLO QCD analysis of polarized inclusive and semi-inclusive DIS data, incorporating target mass and higher twist corrections, and evaluates their impact on polarized parton densities with new COMPASS data.

Contribution

It introduces a combined analysis including 1/Q^2 corrections and new experimental data, providing improved insights into polarized parton densities and higher twist effects.

Findings

Semi-inclusive data significantly influence polarized PDFs.

Higher twist corrections impact the nucleon spin structure functions.

Inclusion of COMPASS data refines the polarized strange quark density.

Abstract

A new combined NLO QCD analysis of the polarized inclusive and semi-inclusive DIS data is presented. In contrast to previous combined analyses, the 1/Q^2 terms (kinematic - target mass corrections, and dynamic - higher twist corrections) in the expression for the nucleon spin structure function g1 are taken into account. The new COMPASS data are included in the analysis. The impact of the semi-inclusive (SIDIS) data on the polarized parton densities (PDFs) and on the higher twist corrections is demonstrated. The controversial behavior of the polarized strange quark density obtained from the fit to the DIS data alone, and a combined analysis of DIS and SIDIS data is discussed.