Valence and sea contributions to the nucleon spin

Abstract

The first moments of the polarized valence parton distribution functions (PDFs) truncated to the wide Bjorken $x$ region $0.004<x<0.7$ are directly (without any fitting procedure) extracted in the next to leading order (NLO) QCD from both COMPASS and HERMES data on pion production in polarized semi-inclusive DIS (SIDIS) experiments. The COMPASS and HERMES data are combined in two ways and two scenarios for the fragmentation functions (FFs) are considered. Two procedures are proposed for an estimation of light sea quark contributions to the proton spin. Both of them lead to the conclusion that these contributions are compatible with zero within the errors.

14 pages; added references

References in corpus (11)

• Global analysis of fragmentation functions for pions and kaons and their uncertainties
• Extraction of Spin-Dependent Parton Densities and Their Uncertainties
• AKK Update: Improvements from New Theoretical Input and Experimental Data
• Dynamical parton distributions of the nucleon and very small-x physics
• Quark helicity distributions from longitudinal spin asymmetries in muon-proton and muon-deuteron scattering
• The Polarised Valence Quark Distribution from semi-inclusive DIS
• Flavour Separation of Helicity Distributions from Deep Inelastic Muon-Deuteron Scattering
• On the role of heavy flavor parton distributions at high energy colliders
• Polarized parton distributions from NLO QCD analysis of world DIS and SIDIS data
• NLO QCD method of the polarized SIDIS data analysis
• Flavor asymmetry of the polarized sea-quark distributions in the proton

Cited by in corpus (2)

• QCD analysis of polarized DIS and the SIDIS asymmetry world data and light sea-quark decomposition
• Direct connection between the different QCD orders for parton distribution and fragmentation functions