The Future of RHIC Physics
A Nuclear Science Advisory Committee subpanel chaired by Bob Tribble of Texas A&M University is charged with recommending priorities for U.S. nuclear physics funding under very constrained budgets. The 2007 Long Range Plan for Nuclear Physics proposed ambitious construction and operations plans under the assumption U.S. funding for physical sciences research would double from 2007 to 2017. Actual budgets are falling far shorter, and the Office of Nuclear Physics (ONP) within the U.S. Department of Energy’s Office of Science has been told to plan for flat budgets for the next several years.
In this climate, it is unlikely ONP can support healthy operations at both the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson National Accelerator Laboratory and the Relativistic Heavy Ion Collider (RHIC) at Brookhaven Lab, together with construction of the Facility for Rare Isotope Beams (FRIB) at Michigan State University (MSU).
This creates a very challenging dilemma for the U.S. nuclear science community at a time when RHIC has essentially completed—and CEBAF is close to completing—substantial upgrades that promise to extend research programs of high visibility and productivity, while the FRIB project has begun with substantial funding from the state of Michigan and MSU.
The Tribble Subpanel held open hearings in Rockville, MD, September 7 to 9, 2012 to gather information on recent accomplishments and plans for these three nuclear physics facilities and research subfields.
A Scenario for Continued RHIC Operations
In preparation for the Tribble hearings, RHIC management developed -- with strong user community input -- a white paper to make the case for continuing RHIC operations as clearly and compellingly as possible. In parallel, interested users have been developing a white paper detailing the science case for a future Electron Ion Collider such as eRHIC, proposed for the mid-2020s. Other relevant activities include securing support letters for RHIC operations from its user community (signed by more than 700 scientists) and industrial partners.
The essence of the case is summarized in the opening paragraph of the RHIC white paper:
“RHIC is in its prime: it is poised to address a host of compelling science questions that remain or have been raised by the important discoveries to date; the facility performance continues to improve dramatically; the user base remains energized and committed; the Nuclear Physics community’s visions for the long-term future of QCD-related research are best realized using RHIC as a primary base.”
The case presented to the Tribble Subpanel placed primary emphasis on the compelling open science questions that can only be addressed at RHIC (or by the combination of RHIC and the Large Hadron Collider at CERN) and RHIC’s clear plans to answer these questions over the coming decade by exploiting recent, ongoing, and proposed facility upgrades.
These science arguments are necessary, but, likewise, the other major nuclear science facilities also worked hard to present strong cases. Thus the case for RHIC also tried to drive home several essential additional points:
- RHIC’s productivity is extraordinary within the field -- over 350 published papers, cumulatively attracting about 35,000 citations, five cover stories in major science magazines and journals, about 350 Ph.D.s produced, and well over 150 tenured faculty and research staff positions filled by RHIC scientists over the past dozen years, with no rate falloff in sight on any of these metrics.
- RHIC’s intellectual connections to other physics forefronts are unusually broad and deep among nuclear physics research areas.
- Foreign investment in RHIC, especially from the RIKEN Institute of Japan, has been extraordinary.
- A cost-realizable path to an electron-ion collider requires taking advantage of -- rather than trying to replace -- the RHIC complex, which would cost ~$2B to build today.
- It is naïve to ignore history’s lessons and assume that funding “freed” by terminating operations at a major facility will be available to redirect as the nuclear science community desires.
As summarized at the end of the RHIC white paper, “The most sensible approach to a several-year budget crisis is to find creative ways to exploit the resources that have been built up by past investments, as long as they are still operating at full efficiency.”