Dynamical Parton Distributions of the Nucleon up to NNLO of QCD

TL;DR

This paper develops and compares new dynamical parton distribution functions of the nucleon at various perturbative orders, analyzing their implications for collider physics and addressing the NuTeV anomaly.

Contribution

It introduces a new dynamical model for nucleon parton distributions, compares it with standard approaches, and explores their phenomenological and astrophysical implications.

Findings

Dynamical PDFs are consistent across different orders and schemes.

The study confirms the perturbative stability of the longitudinal structure function.

Isospin violations help explain the NuTeV anomaly.

Abstract

A new generation of (unpolarized) dynamical parton distribution functions of the nucleon is determined. After introducing basic elements of perturbative QCD, the dynamical model is discussed and compared with the approach to parton distributions used by most other groups ("standard"). Parton distributions sets (with uncertainties) at different orders (LO, NLO, NNLO), using different factorization schemes (\overline{MS}, DIS) and different treatments of heavy quark masses (FFNS, VFNS) are extracted and compared. The astrophysical implications of the dynamical predictions are outlined before focusing on collider phenomenology. There, the relevance and perturbative stability of the longitudinal structure function of the nucleon is studied, and the role of heavy quark flavors in high-energy colliders is analyzed. In addition, it is shown how isospin violations in the nucleon help to explain the so-called "NuTeV anomaly".