[1] Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA
[2] Hope Coll, Dept Phys, Holland, MI 49422 USA
[3] Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA
[4] Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA
[5] Indiana Univ, Dept Phys & Astron, South Bend, IN 46634 USA
[6] Augustana Coll, Dept Phys & Astron, Rock Isl, IL 61201 USA
[7] Concordia Coll, Dept Phys, Moorhead, MN 56562 USA