External Collaborations

A number of research projects involving Institute scientists are carried out at other large national and international accelerator facilities in collaboration with groups from other universities and laboratories worldwide. Many of these are directly complementary to the local experimental program. Others, such as those discussed below, explore other frontiers.

Relativistic Heavy Ion Reactions

Cyclotron Institute scientists also carry out research with relativistic heavy-ion projectiles using accelerators at CERN in Geneva, Switzerland, and at Brookhaven National Laboratory, Long Island, New York. The use of extremely high energies, presently up to 200 GeV /nucleon, allows nuclear matter to be compressed to densities even beyond those present in neutron stars providing the best duplication of conditions corresponding to the early universe that is achievable in the laboratory. Phase changes of ordinary nuclear matter to new forms of matter based on a quark- gluon plasma are predicted to occur in the energy range of the present experiments, and at the increased energies of facilities planned and under construction. Such facilities are the Relativistic Heavy Ion Collider (RHIC) to be operational at BNL in 1999 and the Large Hadron Collider (LHC) underway at CERN.

Development of detectors and software for the BRAHMS collaboration at RHIC is underway at the Cyclotron Institute. Data collected in the measurements will be analyzed at the Cyclotron Institute.

Anti-Quark Studies

At Fermilab, some members of the TAMU group belong to the NuSea collaboration, which is investigating the anti-quark distributions in the nucleon by measuring the relative yield of m⁺m^- pairs in pp and pd collisions. These yields are sensitive to the ratio of   anti-quarks within the proton. The NuSea collaboration is also studying the production of  and resonances in pA collisions to investigate a number of proposed signatures for the quark-gluon plasma at the future relativistic heavy ion collider. Data taking at Fermilab is completed and analysis is underway at present.

Muon Decay

Institute scientists comprise one of the lead groups in a new experiment to measure the Michel parameters in normal muon decay at the TRIUMF "meson factory" in Vancouver, British Columbia The Michel parameters characterize the shape of the positron spectrum from the decay as a function of energy and angle. The Standard Model provides definite predictions for each of the Michel parameters, based on its assumption that the weak interaction is purely left-handed. Any deviation between the measured values and the predictions would be extremely important, since it would require the introduction of right-handed weak currents or other new physics outside the current Standard Model.