Imaging the nucleus with high-energy photons
Spencer R. Klein, Heikki Mantysaari
In the 1930's, .... In the 1960's, Deep Inelastic Scattering experiments showed that protons and neutrons had internal structure: quarks and gluons (collectively, partons), and later experiments showed that the parton momentum distributions are different in heavy nuclei, compared to those in free nucleons. This difference is not surprising; partons are sensitive to their environment, and two gluons from different nucleons may fuse together, for example.
Understanding how quarks and gluons behave in the nuclear environment is a significant focus of modern nuclear physics.... begun to make multi-dimensional pictures of the nucleus, exploring how these alterations are distributed within heavy nuclei. .. started to explore the transverse momentum distribution of the partons in the nuclei, and, using incoherent photoproduction as a probe, study event-by-event fluctuations in nucleon and nuclei parton densities.
This article will explore recent progress in measurements of nuclear structure at high energy, with some emphasis on these multi-dimensional pictures. We will also discuss how a future electron-ion collider (EIC) with high luminosity and center-of-mass energy will make exquisitely detailed images of partons in a nucleus.