Studying the impact of virtuality-dependent nucleon structure modification on spectator-tagged deep inelastic scattering

Measurements of deep inelastic scattering from nuclei have revealed that the partonic structure of bound nucleons differs from that of free nucleons. One hypothesis is that this structure modification primarily occurs in highly virtual nucleons participating in short-range correlations, although distinguishing this from other hypotheses is difficult with inclusive measurements alone. Spectator-tagged deep inelastic scattering, on the other hand, may offer a way to specifically probe the partonic structure of highly-virtual nucleons by detecting the correlated emission of a spectator nucleon. Here, we present a method for calculating a “spectator-tagged” structure function for a nucleus by combining Generalized Contact Formalism’s description of short-range correlations with light-cone convolution formalism to determine the impact of nucleon motion on the structure function. We apply this method to calculate predictions for helium-4, and find that differences in the virtuality-dependence of nucleon structure modification can lead to large measurable changes in the tagged structure function. The recent CLAS12 Short-Range Correlations Experiment, which collected electron scattering data on helium-4 and other nuclear targets, may be able to constrain this virtuality-dependence and help test whether correlations are the origin of the modification of bound nucleon structure.