Electron Ion Collider: The Next QCD Frontier - Understanding the glue that binds us all

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 and, in particular, the focused ten-week program on "Gluons and quark sea a…

Positron Production In Heavy-Ion Collisions

Atomic systems with a nuclear charge Z much greater than 100 exhibit a number of unique features not otherwise found in nature. Two characteristic properties are illustrated in Figs. 1 and 2. In Fig. 1 we have plotted the binding energy of a K-shell electron around hypothetical nuclei up to Z ≈ 200. For Z > 150 the binding energy exceeds the rest energy m e c 2 of the electron; i.e., adding the electron to the nucleus actually diminishes the total mass of the system. At the critical charge Z c ≈ 170–175 the binding energy reaches twice the electron rest mass, the threshold for spontaneous creation of an electron-positron pair. As has been discussed extensively in the literature (Pieper and …

Round Table on Quark-gluon plasma: What is it and how do we find out?