Structure functions in medium and the polarized EMC effect

Abstract

The ratio of the in-medium to free nucleon structure functions for both the unpolarized and polarized case is obtained using the bag model, along with the QMC model to incorporate the in-medium modifications to the structure functions. The unpolarized EMC effect, F₂*(x)/F₂(x), is compared to data and the trend is certainly observed. A prediction of the polarized EMC effect, g₁*(x)/g₁(x), is made and found to be almost identical to the unpolarized case. The in-medium modifications; the σ mean field, Fermi motion, and ω mean field are included into the calculations one at a time to see how the EMC ratio develops for both the unpolarized and polarized case, and to see which in-medium modifications play the dominant role in producing the EMC effect.