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Evidence of Exotic Meson Particle Discovered At Vol. 51 - No. 37 September 19, 1997 BROOKHAVEN NATIONAL LABORATORY Evidence of Exotic Meson Particle Discovered at AGS Researchers at BNL’s Alternating mass of 1.4 GeV after years of select- Gradient Synchrotron (AGS) accelera- ing and analyzing data from products tor have found evidence of a new and of billions of particle collisions made rare subatomic particle called an “ex- during the experiment’s 1994 run. otic” meson. The result was presented to par- This finding at AGS Experiment ticipants of the Seventh International 852, described in the September 1 Conference on Hadron Spectroscopy, issue of Physical Review Letters, helps held at BNL August 25-30 (see story validate the standard model, the cen- on page 2). At the conference, confir- tral theory of modern physics. mation of the E852 result was re- Also, the finding could improve un- ported by what is called the Crystal derstanding of how matter binds to- Barrel collaboration at CERN, the gether at the relatively low energy European particle physics laboratory. level of 18 billion electron volts (GeV). “In some sense, we’ve discovered a The E852 team of 51 scientists, new form of matter,” said Chung. “This graduate students and undergradu- particle had been hypothesized [in ates includes researchers from: BNL, the late 1970s], but it’s never, never Northwestern University, Rensselaer been pinned down. Polytechnic Institute, the University “To find evidence of a particle that of Massachusetts, Dartmouth College, has never been detected before, one and Russia’s Institute for High En- that’s so important to our understand- ergy Physics and the Moscow State ing of elementary particles, is hugely University. satisfying,” Chung continued. “Just The E852 collaboration also in- as satisfying is the fact that we found cludes an Indiana University group, it at the AGS, the home to so many which did not sign the Physical Re- particle discoveries over the decades view Letters publication. “Instead of a and, as our work also shows, a great short letter, the Indiana group wanted machine for high-energy physics.” to write a longer paper, with all the To do the experiment, E852 re- technical and experimental details searchers aimed an 18-GeV beam of included,” said Senior Physicist Suh- negatively charged pions from the Roger Stoutenburgh Urk Chung of BNL’s Physics Depart- AGS at a target of liquid hydrogen. ment, an E852 cospokesman. The target was in a device called a Funded by the U.S. Department of multi-particle spectrometer (MPS), an Energy (DOE) and the National Sci- instrument designed to detect many ence Foundation, the E852 research- different types of particles at once. ers uncovered an exotic meson with a (continued on page 2) At the Alternating Gradient Synchrotron, Experiment 852 researchers (from left, front, counterclockwise) Dennis Weygand, Hans Willutzki, Suh-Urk Chung and Robert Hackenburg are beside the multi-particle spectrometer with which the exotic meson was found. LIA Suports HFBR Review Process, Opposes D’Amato, Forbes Legislation Bromley Calls Anti-HFBR Bill The Board of Directors of the Long Island Association (LIA), the region’s largest business and civic organization, has unanimously passed a resolution ‘Unwise, Unwarranted’ urging that the U.S. Department of Energy be allowed to complete its process of In reaction to the bills introduced into the U.S. Congress by U.S. evaluating the environmental, safety, health and community impact of BNL’s Senator Alfonse D’Amato and Representative Michael Forbes, D. Allan High Flux Beam Reactor (HFBR) and then allowing Energy Secretary Federico Bromley, who is the past President of the American Physical Society and Peña to make a determination as to whether the reactor should be restarted. the former Director of the Office of Science & Technology Policy under Hence the LIA’s resolution opposes the legislation introduced into the U.S. President George Bush, sent them a letter, excerpted below, on Thursday Senate by Senator Alfonse D’Amato and into the House by U.S. Representative September 11, with copies to all members of the House and Senate energy Michael Forbes, which attempts to shut down the reactor permanently without & water development appropriations subcommittees. any evaluation through any process. Dear Senator D’Amato and Representative Forbes: “The decision on the future of Brookhaven National Laboratory’s reactor should be based on science, not politics,” noted LIA President Matthew Crosson On behalf of more than 40,000 physicists throughout the United in a press release issued on Monday, September 15. “To flatly require that the States, the Council of The American Physical Society last April adopted reactor never be reopened, regardless of findings which might determine a statement on neutron scattering facilities. That statement, a copy of otherwise, is unnessary and unwise. It also may be damaging to Long Island’s which I am enclosing, stresses the critical role that neutron science plays future economy. The facilities at the Laboratory, including the reactor, were core in a wide range of technologies across many fields. The statement also component’s of Project Long Island’s determination that Long Island’s future calls attention to the loss of American leadership in this area of research will largely depend on high technology industries.” and the risks that our nation will face if the problem is not soon Crosson continued, “The LIA will urge both houses of Congress to oppose the redressed. legislation introduced by Senator D’Amato and Congressman Forbes. This issue I have learned recently that you and Representative Michael Forbes is too important to Long Island and the country’s future scientific endeavors to have submitted companion legislation that would permanently close be determined by political considerations.” Brookhaven’s High Flux Beam Reactor, one of only four major neutron The LIA President concluded, “It is through research at [the HFBR] that we scattering facilities in our country. From a scientific standpoint, I believe may be able to find cures for Lyme disease, cancer, arthritis and heart disease. that such action is unwise and unwarranted. For almost half a century, Let’s not be so abrupt in our decision to shut out these possibilities. Long Island Brookhaven has been one of the gems in our nation’s scientific enter- deserves better than that.” prise, and the High Flux Beam Reactor has been an integral part of the Established in 1926 and now based in Commack, the LIA represents approxi- laboratory’s outstanding program. mately half of Nassau and Suffolk’s work force and aims to improve Long Island’s Sincerely, D. Allan Bromley business and working environment. Interim Director Announces Five Changes Within BNL’s Organization On Tuesday, September 16, BNL’s Noted Bond, “I want to thank Sue ment of new management systems ning Manager. Becoming Interim Re- Interim Director Peter Bond an- for her heroic efforts over the past and processes.” actor Division Manager is Al Queirolo, nounced that, effective that day, five several years, which were extremely Bill Gunther, who since 1994 has who since 1995 had been that changes had taken place within the stressful and challenging times for been the Manager of the Office of En- Division’s Deputy Manager. The Re- Lab’s interim organization. the Laboratory.” vironmental Restoration (OER), has actor Division operates both BNL’s First, at her request, Sue Davis He continued, “I am extremely been named Interim Associate Direc- High Flux Beam Reactor (HFBR) and stepped down as BNL’s Associate Di- pleased that Dr. Davis has agreed to tor for Reactor, Safety & Security. the Brookhaven Medical Research rector for Reactor, Safety & Security, serve as a senior advisor within the Replacing Gunther as Interim OER Reactor. the position that she has held since Director’s Office [because] her experi- Manager is Bob Howe, who until Tues- “I want to thank Dave for his con- 1992. Davis will remain within the ence and knowledge of the Laboratory’s day was OER’s Deputy Manager. tributions to both the HFBR and the Director’s Office, as a senior advisor ES&H programs and related issues In addition, Dave Rorer, the Man- Laboratory during a particularly diffi- on environment, safety and health will be invaluable as we pursue a ager of the Reactor Division since 1995, cult time at the HFBR,” commented (ES&H). change in our culture and the develop- is now that Division’s Strategic Plan- Bond. Brookhaven Bulletin September 19, 1997 in which they found confirmation of Hadron Spectroscopy ’97: An Exotic Event the new particle. Conference attendee Ted Barnes, The annual International Confer- Oak Ridge National Laboratory and ence on Hadron Spectroscopy has been University of Tennessee, who gave key in the field since its inception, the first plenary-session talk and is and the seventh such conference, held not affiliated with either the E852 or at BNL this year from August 25 to the Crystal Barrel collaborations, had 30, proved to be exceptionally excit- commented earlier on the finding. ing. “This is a very important discov- As the 194 scientists from 19 coun- ery,” Barnes said. “Theorists have pre- tries who attended the conference dicted the existence of exotic hybrid learned, not only had a long-sought- mesons, which contain both quarks after new particle, an exotic meson, and gluons, since the late 1970s, but finally been observed (see story on E852 may have found the smoking page 1), but also, using an entirely gun for their existence. It’s a bench- different approach, another experi- mark that will set the mathematical mental team had uncovered evidence scales for future experimentation and supporting the discovery. theoretical study.” First, the evidence for an exotic Michael Herbert Said Chung, “This could be the meson with a mass of 1.4 billion elec- beginning of a new era in hadron tron volts (GeV) found at Experiment spectroscopy, where multiquarks and 852 at BNL’s Alternating Gradient gluons are accepted as constituents of Synchrotron, was formally presented hadrons.
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