In p+A collisions, these measurements will enable STAR to study Cold Nuclear Matter (CNM).  The proposed FCS and FTS provide kinematic access to very small momentum fractions x in nuclei, facilitating investigations into the dynamics and nonlinear evolution effects in the regime of high gluon-density.  The proposed upgrades and RHIC’s extraordinary versatility are integral to these measurements.

In addition to QCD studies with polarized p+p and p+A collisions, the proposed upgrade will facilitate the determination of QGP properties in A+A collisions through improved measurements of the initial density fluctuations as well as the collective flow seeded by these fluctuations. The proposed forward upgrade will further quantify η/s through improved understanding of initial conditions via measurements of longitudinal flow de-correlation, multiple harmonics and event-shape engineering in A+A collisions, and will allow studies of the possible existence of and limits on hydrodynamics and jet-medium interaction in small systems at RHIC energies.