nCTEQ15HIX -- Extending nPDF Analyses into the High-$x$, Low $Q^2$ Region

TL;DR

This paper extends the analysis of nuclear parton distribution functions into the high-x, low-Q^2 region by incorporating new JLab data and phenomenological corrections, resulting in a refined nPDF set with reduced uncertainties.

Contribution

It introduces the nCTEQ15HIX set, incorporating target mass, higher twist, and deuteron corrections to better describe data in previously excluded kinematic regions.

Findings

Good description of JLab data at high-x and low-Q^2

Reduced uncertainties for up and down quark distributions at large-x

Demonstrates importance of phenomenological corrections in nPDF analyses

Abstract

We use the nCTEQ analysis framework to investigate nuclear Parton Distribution Functions (nPDFs) in the region of large x and intermediate-to-low $Q$, with special attention to recent JLab Deep Inelastic Scattering data on nuclear targets. This data lies in a region which is often excluded by $W$ and $Q$ cuts in global nPDF analyses. As we relax these cuts, we enter a new kinematic region, which requires new phenomenology. In particular, we study the impact of i) target mass corrections, ii) higher twist corrections, iii) deuteron corrections, and iv) the shape of the nuclear PDF parametrization at large-$x$ close to one. Using the above tools, we produce a new nPDF set (named nCTEQ15HIX) which yields a good description of the new JLab data in this challenging kinematic region, and displays reduced uncertainties at large $x$, in particular for up and down quark flavors.