From Hadrons to Electrons - The Road from RHIC to the EIC

The Relativistic Heavy-Ion Collider (RHIC), located at Brookhaven National Laboratory, has been at the forefront of the exploration of the fundamental structure of strongly interacting matter for over two decades. Quantum Chromodynamics (QCD), the theory of the strong nuclear force, has many interesting, emergent properties. RHIC continues to make important discoveries in both Hot and Cold QCD, from the quark gluon plasma (QGP) formed in collisions of heavy ions, with remarkably small viscosity, to the spin structure of the proton. Small systems, which form QCD matter with signatures of collective behavior similar to those observed in a QGP, have added to the complexity of the QCD story. RHIC has been extremely versatile and can collide many different species and is the only collider with polarized proton beams. The Electron-Ion Collider (EIC) will be an innovative, large-scale facility to be constructed at Brookhaven, utilizing key components of the RHIC complex. The EIC will study nucleons and nuclei with the most powerful electron microscope ever built, in order to address some of the most fundamental questions such as the origin of nucleon mass and spin, and the emergent properties of a dense system of gluons. I will discuss key discoveries that have been made at RHIC, the critical measurements that need to be made in the last years of operations to finish the science mission, and how the scientific program in QCD will be transformed with the unprecedented reach and precision available at the EIC.