NLO PDFs from the ABMP16 fit

TL;DR

This paper presents a comprehensive global fit of parton distribution functions (PDFs) at next-to-leading order (NLO), including the strong coupling constant and quark masses, using the same data as previous NNLO fits, providing NLO PDFs for consistent QCD predictions.

Contribution

It introduces NLO PDFs based on the ABMP16 analysis, complementing existing NNLO PDFs, and details the determination of the strong coupling constant and quark masses at NLO.

Findings

NLO PDFs are provided for $n_f=3,4,5$.

The NLO strong coupling constant at $M_Z$ is 0.1191.

The NLO $ar{ ext{MS}}$ scheme is used for all parameters.

Abstract

We perform a global fit of parton distribution functions (PDFs) together with the strong coupling constant $\alpha_s$ and the quark masses $m_c$, $m_b$ and $m_t$ at next-to-leading order (NLO) in QCD. The analysis applies the $\overline{\mathrm{MS}}\, $ renormalization scheme for $\alpha_s$ and all quark masses. It is performed in the fixed-flavor number scheme for $n_f=3, 4, 5$ and uses the same data as the previous fit of the ABMP16 PDF at next-to-next-to-leading order (NNLO). The new NLO PDFs complement the set of ABMP16 PDFs and are to be used consistently with NLO QCD predictions for hard scattering processes. At NLO we obtain the value $\alpha_s^{(n_f=5)}(M_Z) = 0.1191 \pm 0.0011$ compared to $\alpha_s^{(n_f=5)}(M_Z) = 0.1147 \pm 0.0008$ at NNLO.