The Electron Ion Collider Meeting at Stony Brook University
By Abhay Deshpande
The electron ion collider (EIC) enthusiasts met at Stony Brook University’s Wang Center on December 7 and 8, 2007 for their first meeting after the Nuclear Science Advisory Committee’s (NSAC) Long Range Plan (LRP) was approved by the full NSAC on December 3 and 4, 2007 in Washington. The organizers of the SBU meeting were pleasantly surprised by their enthusiasm, and had to change the room before the meeting to accommodate the larger number of participants. The final tally was about 110 registered participants. Indeed there was no sign of LRP fatigue, only the determination to move forward, building on the recent momentum. The meeting webpage is http://web.mit.edu/eicc/SBU07/ and all presentations are linked.
The first morning, chaired by Allen Caldwell (MPI, Munich) was dedicated to low x physics, single spin asymmetries and the possible connections between them on based on recent and not so recent theoretical ideas. Al Mueller (Columbia) opened the meeting with a broad exposition of the physics of low x and spin that is relevant to making the science case for the EIC. Stan Brodsky (SLAC) emphasized single spin asymmetries and other novel phenomena, which have fascinated spinners around the world in the recent past. Les Bland (BNL) followed these two theoretical talks by discussion of what of is possible with the present collider and forward detectors at RHIC.
Bob Tribble (Texas A&M), the present chair of NSAC, and the chief architect of the just completed long-range planning report, presented his view of the EIC in the LRP report. He was cautiously optimistic about the future. He emphasized the need for the EIC enthusiasts to prepare a case for EIC that is not only convincing to the scientists involved in the physics of QCD around the world, but is also compelling to scientists in other branches of nuclear and particle physics. Not surprisingly, a detailed and at times passionate discussion ensued following Bob’s presentation.
In the afternoon the podium was taken over by accelerator scientists, in a session chaired by Lia Merming (Jlab). The speakers presented the status of designs from BNL (eRHIC) and from Jlab (ELIC), and summarized the new developments in the designs in the last few months. The speakers were S. Derbenev and A. Bogacz from Jlab, and V. Ptitsyn and Y. Hao from BNL. Vladimir Litvinenko (BNL) presented ideas about coherent electron cooling on his and S. Derbenev’s behalf, applicable to both designs of EIC. Wolfgang Lorenzon (Michigan) presented the status of e-beam polarimetry studies initiated in a recent workshop on EIC and indicated that ~1% absolute accuracy in e-beam polarimetry seems possible for the EIC.
Since the last EIC meeting a third serious idea for an electron ion collider has evolved as a possible long term future option. John Dainton (Liverpool, UK) presented the physics case and the status of that project. The idea is based on a ~70 GeV ERL similar in its ideas being discussed at BNL for its eRHIC, (except the energy itself) colliding with the existing proton beams of LHC in one interaction point. The resulting center of mass energy of 1.4 TeV would allow searches for phenomena beyond the standard model and also explore some aspects of high density gluonic matter at very low x. The LHeC is now being presented and discussed in various international circles including the CERN management. Beyond the obvious physics connections, the EIC collaborators on both sides of the Atlantic should be interested in possible collaborations on machine and detector R&D issues in the near and far future.
The morning session on 8th December was chaired by Steve Vigdor, BNL’s new Associate Lab Director. The opening session included short presentations and discussion of physics topics that so far have been beyond the range considered so far by the EIC proponents, somewhat along the line suggested in Bob Tribble’s talk on the first morning. Short presentations by Stan Brodsky, Larry McLerran (BNL) and Steve Vigdor lead to interesting discussions and assignments for various EICers to follow up on some of the ideas presented. Mark Strikmann (PSU) and Andrzej Sandacz (Warsaw) presented their theoretical and experimental studies, and simulations of vector meson production with the EIC.
The rest of the day was planned by the working group conveners. Richard Milner (MIT) chaired these sessions. The e-p physics working group activities were summarized by A. Bruell (Jlab) with some existing studies and some new ideas on how the group plans to proceed in the near future. This was followed by a short presentation by C. Weiss on deeply virtual vector meson production with some theoretical issues. The e-A physics working group decided to present four short presentations by some of their new entrants in their working group: R. Longacre, M. Lamont, and G. Soyez, all of BNL, and C. Marquet (Columbia). Yousef Makdisi (BNL) then made a short presentation on the status of hadron beam polarimetry emphasizing the significant work to be done in future to reduce the uncertainty in hadron beam polarimetry to compete with the e-beam polarimetry. Bernd Surrow (MIT) summarized the needs of the future EIC detector, along with some suggestions to address some of the R&D issues for both EIC collider concepts. A need to develop a time line for various detector R&D items that will allow the collaboration to move towards and meet DOE’s various “Critical Decision” (CD) requirements and the next LRP was emphasized during the presentation and in the discussion that followed.
Rolf Ent (Jlab) ended the meeting with the invitation to all participants and readers of RHIC News to attend the next meeting of the EIC enthusiasts at Hampton University to be held May 19-23, 2008.
The meeting was very successful, not only on the EIC project issues, but also socially. A lot of new faces were introduced in presentations. The meeting banquet was held at Sunwood, the residence of the President of Stony Brook University on Friday night. The chair of the meeting was impressed and extremely happy that people could find their way to Sunwood without getting lost, even in the dark. This is certainly a great sign for the EIC project…. we’ll definitely find our way!