R.G. Milner2nd EIC Workshop Summary and Outlook science case machine design EIC realization

R.G. Milner2nd EIC Workshop Why EIC? Because it is essential for the study of the fundamental structure of matter beyond 2010 to understand nucleon and nuclei and to test QCD Context: particle physics search for `God particle’ astrophysical speculation on dark matter and energy On the timescale of EIC we expect full ab initio QCD calculations of many experimental observables

R.G. Milner2nd EIC Workshop What will we learn from EIC? Spin structure of the nucleon - g p 1 (x) at low x dramatic QCD prediction - gluon and sea quark polarization - Bjorken sum rule QCD test - new (GPD, transversity) parton distributions Partonic understanding of nuclei hot QCD - gluon momentum distribution in nuclei - fundamental explanation of nuclear binding - saturation

R.G. Milner2nd EIC Workshop Machine Design Mainline machine design reaches luminosity ~ nucleons cm -2 s -1 ring-ring eRHIC design Realistic (but aggressive) design based on RHIC and B factory performance High luminosity requires electron cooling Cost framework understood ~ 300 – 500 M$ Other concepts (eRHIC linac-ring, ELIC) should be vigorously pursued to determine realistic designs

R.G. Milner2nd EIC Workshop Luminosity At any luminosity there will be measurements which are statistically marginal There is a substantial and excellent part of EIC case realizable without electron cooling of ion beam spin structure of nucleon partonic understanding of nuclei It is reasonable to consider scenarios where EIC gets underway without electron cooling and the path to full luminosity is staged in time

R.G. Milner2nd EIC Workshop Realization of EIC 2001 Long Range Plan (LRP) endorsed science favorably and recommended support for R&D Anticipate next LRP to begin in 2005 Wish to present science case and machine design at upcoming LRP with goal of receiving high priority for new construction of a high luminosity electron ion collider

R.G. Milner2nd EIC Workshop Issues Maintain and enhance community wide and international support Focus and sharpen scientific case Continue to develop machine designs and options Several meetings planned for later this year - eRHIC ZDR review ~ May workshops on GPDs, saturation ~ late summer - meeting to organize final preparation for LRP ~ early 2005

R.G. Milner2nd EIC Workshop EIC Steering Committee A. Caldwell (MPI Munich) A. Deshpande (StonyBrook) R. Ent (JLab) G. Garvey (LANL) R. Holt (ANL) E. Hughes (Caltech) K.-C. Imai (Kyoto Univ.) R. Milner (MIT) P. Paul (BNL) J.-C. Peng (Illinois) S. Vigdor (Indiana Univ.)

R.G. Milner2nd EIC Workshop Summary 2nd EIC workshop at JLab an outstanding success Clear and substantial progress since 1 st EIC workshop at BNL Science case for EIC becomes more compelling Solid machine design for luminosity of ~ nucleon cm -2 s -1 together with more futuristic concepts having potential for increased luminosity Essential over next year to prepare for aggressive engagement in the upcoming Long Range Planning Exercise