On the universality of the $x$ and $A$ dependence of the EMC effect and its relation to parton distributions in nuclei

Abstract

It is shown that the latest results from the NMC (CERN) and E665 (Fermilab) groups on $F_2^A(x)/F_2^D(x)$ obtained in the shadowing region bring new evidence of the universal $A$ dependence of distortions made in a free-nucleon structure function by a nuclear medium. The observed universality implies that one can consider separately hard ($A\le$ 4) and soft ($A>$ 4) parton distribution distortions. Soft distortions, which result in differencies between the deep-inelastic scattering cross-sections for nuclei with masses $A_1$, $A_2\ge$ 4, can be explained as a consequence of the nuclear density variation, independent of $x$ in the range 0.001 $\le x\le$ 0.7. It is found that nuclear shadowing begins at $x_{\mathrm{I}}$ = 0.0615 $\pm$ 0.0024, independent of $A$, which is consistent with models that allow for three-parton recombination processes.

11 pages (LaTeX) and 4 Postscript figures in uuencoded compressed file

References in corpus (4)

• Parton Distributions of the Proton
• A Re-Evaluation of the nuclear Structure Function Ratios for D, He, Li, C and Ca
• The Structure Function Ratios F2(Li)/F2(D) and F2(C)/F2(D) at small x
• Shadowing in Inelastic Scattering of Muons on Carbon, Calcium and Lead at Low XBj

Cited by in corpus (8)

• Scale evolution of nuclear parton distributions
• Nuclear shadowing
• POLRAD 2.0. FORTRAN code for the Radiative Corrections Calculation to Deep Inelastic Scattering of Polarized Particles
• Bethe-Salpeter approach with the separable interaction for the deuteron
• Evolution of the nucleon structure in the lightest nuclei
• Effects of a dynamical role for exchanged quarks and nuclear gluons in nuclei: multinucleon correlations in deep-inelastic lepton scattering
• Space-time structure of a bound nucleon
• The $x$-Region of Shadowing Corrections in Nucleon Structure Functions