Panel Probes Possibilities in Particle Physics

"The Future of U.S. High-Energy Physics" is a big topic that was addressed from different points of view by participants in a special session at the meeting of the Division of Particles and Fields (DPF) in Williamsburg, VA in late May.

Participating were APS President William F. Brinkman, Director of NSF's Physics Division Joseph L. Dehmer, Director of the Department of Energy's Office of Science Raymond L. Orbach, and DPF Chair Stanley G. Wojcicki. The panel was chaired by APS Past President George Trilling.

Photo by Jessica Clark. Left to right: Stanley Wojcicki, Raymond Orbach, Joseph Dehmer, William Brinkman.

Orbach talked about some areas of research in high-energy physics that he felt were exciting and deserving of a high level of support from his office. One was the Large Hadron Collider, now under construction at the CERN laboratory in Geneva with significant help from US scientists. The LHC will be operational in about five years, and the particle physics community is already looking ahead to the next big accelerator, which will probably be an electron-positron linear collider. Orbach stressed that this must be an international effort from the start, regardless of where the machine is built, and expressed concern that "we don't have a mechanism to bring governments together to work towards this end."

Second on Orbach's list was the general area of astro-particle physics and the problem of dark energy. "The public at large is interested in these philosophical concepts" Orbach stated, and added that their study is "important philosophically, almost religiously." He particularly mentioned the SNAP (SuperNova/Acceleration Probe) experiment proposed by scientists at Berkeley's Lawrence Radiation Laboratory to measure the acceleration of the universe, using distant supernovae, much more accurately than has been possible to date. "In putting together the 2004 budget we have made a significant commitment to SNAP," Orbach said.

Orbach also called for a major effort to improve US computing capabilities. He pointed out that the Japanese have built a computer, the Earth Simulator, that studies the weather and is roughly 50 times faster than anything that exists in the US. "To find ourselves second on an international scale is a national disaster," he said.

The study of quantum chromodynamics (the theory of strong interactions) on a lattice is an excellent way to develop leading-edge computers, Orbach maintained. "QCD simulation leads the way," he said, calling it "as fundamental an exercise as experiment and theory."

Dehmer said that despite current problems with funding, "the public enjoy and are impressed by new developments in science." He noted that although the FY2002 NSF budget was up 4.4%, the level of funding for individual investigators in physics was actually down about 10% because of the necessity to support facilities, new initiatives like Physics Frontier Centers, and other NSF-wide commitments. He added that the overall FY2003 request was down by 1-2% but expected nevertheless that the situation would improve for the individual investigators.

"Broad support for physical science has been strong and coherent" on Capitol Hill, Dehmer said, and predicted that the effects of that support would be evident when the Congressional appropriations were passed in the fall.

Not being a particle physicist himself, Brinkman took a broader view and addressed the question of whether physics as a discipline was in some kind of malaise. He cited a variety of reasons for this perception, and pointed out that in many cases the reality was quite different.

Although there has been declining enrollment in physics, and PhD production now stands at about 1200/year, Brinkman noted that when production reaches 1500 unemployment can result, and as long as it stays above about 1000 there tends to be an adequate supply of new physicists. He concluded that "this is not a major aspect" of any possible malaise.

He did agree that the number of Americans going into physics has gone way down, and suggested that this could be ameliorated if the funding agencies would significantly increase the stipends that they offered to students, for example with NSF Fellowships.

Another factor Brinkman cited was the perception that there is an increasing emphasis on biology at the expense of physics. But he noted that "some physicists" had invented a way to do very rapid decoding of DNA, which stimulated great advances in biology. He said there were "opportunities in biology for physicists that we shouldn't ignore", and remarked that "if you can't fight 'em, join 'em."

"Physics has become irrelevant to our quality of life" was another complaint that Brinkman felt was highly overstated. He said that not only was the Web invented by physicists, but the entire internet is based on improved optical communication, and cited the optical amplifier as "one of the enabling things invented by physicists."

Brinkman echoed Orbach and Dehmer in asserting that "concepts in astrophysics, cosmology and particle physics have greatly piqued the interest of the general public." He denied that it looks like physics is in trouble because one cannot go on building bigger machines, pointing to the exciting results from the neutrino observatories, and expressing confidence in physicists' abilities to find "new directions, new ways of doing things."

Summing up, Brinkman urged his audience to "think of yourselves as physicists-you are one end of a spectrum from the curiosity driven to the very applied. You are part of a very large community that does all kinds of physics."

Wojcicki agreed with Orbach's contention that the next accelerator had to be international from the start. "The next major accelerator facility, a TeV scale linear collider, has to be an international effort," he said, but added that "construction of a multi-billion dollar scientific facility as an international enterprise will not be a piece of cake. In addition, our political system with its separate Executive and Legislative branches and our funding system, with its year to year appropriations, do not make the situation any easier."

He also remarked on internal problems within high-energy physics, especially as they affect younger people. "What does a graduate student do in a 500 member collaboration? How does she manage not be lost? How does he manage to have his work recognized?" he asked, adding that "the experimental timescale today exceeds the natural time scales of a graduate career, postdoc tenure, or appointment length of an Assistant Professor. The senior people in the field.must address [this] issue and search for solutions which will overcome these inherent difficulties that are of such paramount importance to our younger colleagues."