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An International Lab

The BaBar detector at the SLAC B Factory. (Photo by Peter Ginter. Click for larger image.)

This week, physicists from around the world converge at SLAC to celebrate historic advances and map future steps in high energy physics at meetings of the International Committee for Future Accelerators and the BaBar Collaboration. And today, the B-Factory Symposium celebrates the stunning results from the BaBar detector, PEP-II storage ring, and the BaBar Collaboration. Among the first completely international projects at the lab, this collaboration has been a key player in the emergence of large-scale global physics and in SLAC's evolution as an international laboratory.

Some describe SLAC in its first decades as a world-renowned but distinctly individual—even insular—physics powerhouse, recognized for its Nobel laureates and particle physics firsts.

"Before BaBar, SLAC was obviously a star in our field, an international star, but a national lab," said Gerard Bonneaud, research director at France's National Center for Scientific Research. Bonneaud first worked at SLAC in 1980 and now chairs the SLAC User's Organization as a visiting researcher. With BaBar, Bonneaud said, "SLAC is still an international leader but also an international lab." Scientists from nine nations gathered at the first BaBar meeting in 1993, bringing their expertise and their countries' valued traditions in physics research. Bonneaud built the BaBar group at École Polytechnique, one of five French institutions to join the collaboration. "My whole energy was to try to contribute to a spirit of real collaboration," he said, "physicists working together, not French, English, etc."

"I expected national priorities to get in the way of international collaboration—and they didn't," said John Fry, University of Liverpool director of postgraduate teaching, who was among the first five UK members of the nascent BaBar collaboration. Fry and others worked hard to convince the UK funding agency to put up the money to make a significant contribution to BaBar. "In the end," Fry said, "that was achieved because of the sheer weight of numbers of UK scientists who wanted to do this physics."

"German physicists were very focused on work at DESY and CERN," said Klaus Schubert, professor emeritus of the Technical University of Dresden. Schubert visited SLAC in early 1993 to explore possible German participation, and became an early member of BaBar's executive board. "Of course, when BaBar had first results in 2000 it was very easy to have [German participation] continued, because the beautiful results convinced the particle physicists." Schubert is now nearing completion of his BaBar analyses, and expects to publish the third of three 2008 papers soon. He will speak about quark mixing at the B-Factory Symposium today.

"The BaBar governance allowed a real international integration inside the collaboration," said University of Pisa particle flavor physicist Marcello Giorgi, who led the Italian participation in BaBar and served as BaBar's third spokesperson. "The international structure and the International Finance Committee have built the BaBar image of coherent, smooth and positive cooperation in science."

BaBar's international model for scientific and fiscal collaboration provided stability to carry out a large-scale and complex venture. The collaboration's International Finance Committee includes heads of funding agencies from each participating country. When inevitable funding hiccups have arisen, the countries have shuffled obligations to keep the project moving. Participants have all been enthusiastic and eager for success, said SLAC Director Emeritus Jonathan Dorfan. Especially during the crucial early meetings to launch BaBar, "no one wanted to leave the table being the one to impede progress," Dorfan said. "That dynamic was very powerful."

Several of the collaborators describe BaBar's model as part of a change toward increasingly global collaboration in the worldwide physics community, which influenced how each participating organization would collaborate going forward. SLAC is no exception. "It started with the Stanford Linear Collider," Dorfan said. The SLC broke new ground at SLAC, in that it was a collaboration of not only U.S. but also British, Canadian and Italian scientists. "Then came BaBar," he said, "which was just completely different." With at least half its funding from international partners, and its four first spokespersons from non-U.S. institutions, BaBar heralded a far more multi-national SLAC.

From establishment of the Stanford Guest House to ease travel expense and create a sense of community for international visitors, through increased openness to internationally-run rather than lab-controlled projects, SLAC has changed, Dorfan said. "The lab became, in all aspects, truly international."

—Shawne Workman
SLAC Today, October 27, 2008