Shadowing in Inelastic Scattering of Muons on Carbon, Calcium and Lead at Low XBj

TL;DR

This paper reports on nuclear shadowing effects observed in inelastic muon scattering on various nuclei, showing how shadowing varies with Bjorken-x and atomic number, and comparing it to photoproduction results.

Contribution

The study provides new measurements of nuclear shadowing in muon scattering across multiple nuclei at high energies, extending understanding of nuclear effects at low Bjorken-x.

Findings

Shadowing increases as XBj decreases.

Shadowing effect shows A dependence consistent with photoproduction.

No significant nu or Q^2 dependence at fixed XBj.

Abstract

Nuclear shadowing is observed in the per-nucleon cross-sections of positive muons on carbon, calcium and lead as compared to deuterium. The data were taken by Fermilab experiment E665 using inelastically scattered muons of mean incident momentum 470 GeV/c. Cross-section ratios are presented in the kinematic region 0.0001 < XBj <0.56 and 0.1 < Q**2 < 80 GeVc. The data are consistent with no significant nu or Q**2 dependence at fixed XBj. As XBj decreases, the size of the shadowing effect, as well as its A dependence, are found to approach the corresponding measurements in photoproduction.