[1] Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA
[2] Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA
[3] Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA
[4] Bulgarian Acad Sci, Inst Nucl Res & Nucl Energy, BU-1784 Sofia, Bulgaria
[5] Univ Warsaw, Inst Theoret Phys, PL-00681 Warsaw, Poland
[6] Warsaw Univ Technol, Inst Phys, PL-00662 Warsaw, Poland