Understanding the emergence of nucleons and nuclei and their interactions from the properties and dynamics of quarks and gluons in Quantum Chromodynamics (QCD) is a fundamental and compelling goal of nuclear science. A high-energy, high-luminosity polarized electron-ion collider (EIC) will be needed to explore and advance many aspects of QCD studies in the gluon dominated regions in nucleon and nuclei. The federal Nuclear Science Advisory Committee unanimously approved a high-energy electro-ion collider to explore a new frontier in physics research. In fact, the committee calls the collider the country's next "highest priority" in new facility construction, and is one of four main recommendations contained in its 2015 Long Range Plan for Nuclear Science. Two proposals for the EIC are being considered in the U.S.: one each at Jefferson Laboratory (JLab) and at Brookhaven National Laboratory (BNL). An overview of the physics opportunities an EIC presents to the nuclear science community in future decades is presented.

This volume contains the proceedings of the Workshop on Physics with an Electron-Polarized Ion Collider (EPIC-99), jointly sponsored by the Indiana University Cyclotron Facility and Nuclear Theory Center, and the Institute for Nuclear Theory, University of Washington. It was held in Bloomington, Indiana, April 8-11, 1999. The purpose was to discuss important new physics phenomena which could be investigated with a high-luminosity asymmetric collider consisting of a beam of polarized electrons (with energy roughly 5 GeV), and a beam of polarized protons or other light ions of approximately 40 GeV energy. The Workshop brought together experts in the field who highlighted the unique potential for such a facility, and compared the prospects and challenges for this collider with present and proposed facilities around the world.The proceedings of this Workshop summarize our currently available knowledge on the physics potential for a polarized asymmetric collider. It provides a unique collection of information on the opportunities which such a facility would provide.

Understanding of protons and neutrons, or "nucleons"â€"the building blocks of atomic nucleiâ€"has advanced dramatically, both theoretically and experimentally, in the past half century. A central goal of modern nuclear physics is to understand the structure of the proton and neutron directly from the dynamics of their quarks and gluons governed by the theory of their interactions, quantum chromodynamics (QCD), and how nuclear interactions between protons and neutrons emerge from these dynamics. With deeper understanding of the quark-gluon structure of matter, scientists are poised to reach a deeper picture of these building blocks, and atomic nuclei themselves, as collective many-body systems with new emergent behavior. The development of a U.S. domestic electron-ion collider (EIC) facility has the potential to answer questions that are central to completing an understanding of atoms and integral to the agenda of nuclear physics today. This study assesses the merits and significance of the science that could be addressed by an EIC, and its importance to nuclear physics in particular and to the physical sciences in general. It evaluates the significance of the science that would be enabled by the construction of an EIC, its benefits to U.S. leadership in nuclear physics, and the benefits to other fields of science of a U.S.-based EIC.

This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on the structure and interactions of gluon-dominated matter, with the intent to articulate it to the broader nuclear science community. It was commissioned by the managements of Brookhaven National Laboratory (BNL) and Thomas Jefferson National Accelerator Facility (JLab) with the objective of presenting a summary of scientific opportunities and goals of the EIC as a follow-up to the 2007 NSAC Long Range plan. This document is a culmination of a community-wide effort in nuclear science following a series of workshops on EIC physics over the past decades and, in particular, the focused ten-week program on "Gluons and quark sea at high energies" at the Institute for Nuclear Theory in Fall 2010. It contains a brief description of a few golden physics measurements along with accelerator and detector concepts required to achieve them. It has been benefited profoundly from inputs by the users' communities of BNL and JLab. This White Paper offers the promise to propel the QCD science program in the US, established with the CEBAF accelerator at JLab and the RHIC collider at BNL, to the next QCD frontier.

This volume contains the proceedings of the Workshop on Physics with an Electron-Polarized Ion Collider (EPIC-99), jointly sponsored by the Indiana University Cyclotron Facility and Nuclear Theory Center, and the Institute for Nuclear Theory, University of Washington. It was held in Bloomington, Indiana, April 8-11, 1999. The purpose was to discuss important new physics phenomena which could be investigated with a high-luminosity asymmetric collider consisting of a beam of polarized electrons (with energy roughly 5 GeV), and a beam of polarized protons or other light ions of approximately 40 GeV energy. The Workshop brought together experts in the field who highlighted the unique potential for such a facility, and compared the prospects and challenges for this collider with present and proposed facilities around the world. The proceedings of this Workshop summarize our currently available knowledge on the physics potential for a polarized asymmetric collider. It provides a unique collection of information,on the opportunities which such a facility would provide.