Deep-inelastic scattering on nuclei: Impulse approximation and mesonic corrections

Abstract

We present a unified relativistic covariant description of nucleon binding and mesonic corrections to nuclear structure functions in terms of a Feynman diagram approach. The connection between considerations in the infinite momentum frame, where the parton model can be applied, and in the nucleus rest frame is discussed. A new method to estimate mesonic corrections in terms of a nuclear model based on effective meson-nucleon theory is proposed. We apply this method to evaluate the mean mesonic excess in nuclei n mes , the mean mesonic momentum squared k mes 2 , and to derive the bounds on pion distribution function in nuclei. We find that the bulk of the EMC effect at x > 0.1 is reproduced within the impulse approximation with mesonic corrections, while this approximation fails to explain new EMC data at x < 0.1.