This award will support ongoing collaboration between U.S. and Swedish physicists on the topic of high energy heavy ion interactions. Drs. R. Jeffrey Wilkes, Thompson H. Burnett and Jeri J. Lord of the University of Washington will continue their research efforts with Dr. K.N. Ingvar Otterlund and his laboratory group at the University of Lund. Experiments will be performed at the CERN heavy ion facility in Geneva, Switzerland, and Brookhaven National Laboratory in the United States, and the analysis and reduction of the data will be conducted at the respective individual universities. The heavy ions Si-28 and S-32 will be accelerated to energies of 15-200 GeV/nucleon and then directed onto emulsion chamber detectors, which are arrays of nuclear emulsion plates permitting extremely precise observations of produced particle tracks. The major purpose of the experiment will be to search for the new state of nuclear matter, the quark-gluon plasma, which is predicted theoretically to be most likely created in heavy ion collisions. The experiment represents a unique opportunity to study this high density phase of matter, since the new CERN sulfur ion beam will be nearly 50 times more energetic than any previous accelerator beams of particles having atomic numbers greater than Z=16. This project combines the expertise of two of the leading international research groups in the use of emulsion techniques for the study of nuclear interactions. The proposed investigation is important and timely in making use of newly available energetic beams of heavy ions.
