nCTEQ15: Global analysis of nuclear parton distributions with uncertainties in the CTEQ framework

TLDR

The paper introduces the nCTEQ15 nuclear parton distribution functions with quantified uncertainties. The authors extend CTEQ proton PDFs to nuclei up to Pb208 using DIS, DY, and RHIC pion data, applying a Hessian method with rescaled eigenvectors to estimate uncertainties and analyzing data correlations with nPDF flavors. The resulting nCTEQ15 set is compared with recent global fits from other groups.

Abstract

We present the new nCTEQ15 set of nuclear parton distribution functions with uncertainties. This fit extends the CTEQ proton PDFs to include the nuclear dependence using data on nuclei all the way up to 208^Pb. The uncertainties are determined using the Hessian method with an optimal rescaling of the eigenvectors to accurately represent the uncertainties for the chosen tolerance criteria. In addition to the Deep Inelastic Scattering (DIS) and Drell-Yan (DY) processes, we also include inclusive pion production data from RHIC to help constrain the nuclear gluon PDF. Furthermore, we investigate the correlation of the data sets with specific nPDF flavor components, and asses the impact of individual experiments. We also provide comparisons of the nCTEQ15 set with recent fits from other groups.