Leonard Gamberg, Pennsylvania State University (Principal Investigator)

One of the major objectives of nuclear physics research  is to understand and quantify how hadrons and nuclei emerge from, and are
structured in terms of the fundamental constituents of matter.  It is predicted from Quantum Chromodynamics (QCD),  the gauge theory
of quark and gluon interactions, which in principle describe hadrons and nuclei as bound and ultimately confined state of quarks and
gluons (partons), that  the internal landscape of hadrons can be determined from deep inelastic scattering experiments.  Asymptotic
freedom  makes  it possible  to utilize the  theoretical formalism of QCD factorization to quantify the partonic structure and dynamics
of hadrons from  deep inelastic scattering  measurements where partons become weakly coupled when hadrons are probed at
sufficiently short time and distance scales. QCD factorization predicts that the measured scattering cross sections can be factorized
in terms of non-perturbative and perturbative factors.  While decades of high-energy experiments have provided data allowing for the
high resolution of the 1-dimensional (1-D) longitudinal momentum structure of hadrons,   the information on the transverse momentum
structure of hadrons is comparatively less well known.  Achieving a 3-dimensional (3-D) map of the internal structure of hadrons
requires sensitivity to both collinear and transverse parton degrees of freedom. Uncovering the 3-D landscape of hadrons is a major
the goal of high energy nuclear physics facilities such as the Relativistic Heavy Ion Collider (RHIC, BNL), the Continuous Electron Beam Accelerator Facility (CBAF, JLAB), the COMPASS  and Amber experiments (CERN) and the past HERMES (DESY) Experiments, and
the future Electron-Ion Collider (EIC, BNL).