Can a Highly Virtual Nucleon Experience Final State Interactions in Electron-Nucleus Scattering?

We discuss how the virtuality of the struck particle may affect the final state interactions in electron-nucleus scattering. The extent to which short range correlations inhibit rescattering taking place within the range of the repulsive core of the NN interaction is quantitatively analyzed. The possible modifications of the nucleon-nucleon scattering amplitude associated with the virtuality is also studied, within the framework of a nonrelativistic model. The results suggest that the on shell approximation can be safely employed in the kinematical region relevant to the analysis of the available inclusive data at large momentum transfer and low energy loss.Comment: 11 pages, 3 figures available upon request, Revte

Extraction of the Ratio of the Neutron to Proton Structure Functions from Deep Inelastic Scattering

We study the nuclear ($A$) dependence of the European Muon Collaboration (EMC) effect at high values of $x$ ($x \geq 0.6$). Our approach makes use of conventional nuclear degrees of freedom within the Relativistic Impulse Approximation. By performing a non-relativistic series expansion we demonstrate that relativistic corrections make a substantial contribution to the effect at $x \gtrsim 0.6$ and show that the ratio of neutron to proton structure functions extracted from a global fit to all nuclei is not inconsistent with values obtained from the deuteron.Comment: 12 pages, 2 figures available upon request, Revte

The Strong Coupling Constant from Hadron Structure Phenomenology

We present recent developments on the role of the running coupling constant at the intersection of perturbative and nonperturbative QCD. A number of experiments show a smooth transition from small to large scales given by the four-momentum transfer in the reactions. This is at variance with perturbative QCD where the running coupling constant becomes infinite when the scale equals $\Lambda_{{\tiny QCD}}$. Approaches using an effective coupling constant could help interpret the opposite trend of data as compared to standard perturbative QCD predictions. We give an overview of the role of the coupling constant in the procedure to match nonperturbative hadronic model to perturbative QCD and we propose an extraction of an effective coupling constant from inclusive electron proton scattering data at large Bjorken x.Comment: To appear in the proceedings of the QCD Evolution Workshop, JLab, May 14-17, 2012. Includes ws-ijmpcs.cl