QCD Structure of Hard Processes in Nuclear Interactions

Carlos Granados, Florida International University

Hard photodisintegration of a nucleon nucleon system (NN) is studied within the framework of the hard rescattering model (HRM). Hard NN breakup is described through the HRM by explicitly invoking QCD degrees of freedom; the incoming photon is absorbed by one nucleon's valence quark that then undergoes a hard rescattering reaction with a valence quark from the second nucleon producing two nucleons emerging at large transverse momentum. Parameter free cross sections for pp and pn break up channels are then calculated through the input of experimental cross sections on pp and pn elastic scattering. The computed cross section for pp breakup (particularly its predicted energy dependency) is in good agreement with recent experimental data. Predictions on spectator momentum distributions and helicity transfer are also presented. Motivation for the study of Delta-Isobar production in hard photodisintegration of the deuteron and further applications are also discussed.