D. H. Davis^*, R. Levi Setti, M. Raymund, O. Skjeggestad^†, and G. Tomasini^‡

• The Enrico Fermi Institute for Nuclear Studies and Physics Department, The University of Chicago, Chicago, Illinois

J. Lemonne, P. Renard^§, and J. Sacton

• Université Libre de Bruxelles, Bruxelles, Belgium

• ^*Now at University College London, London, England.
• ^†Now at CERN, Geneva, Switzerland.
• ^‡Now at University of Genoa, Genoa, Italy.
• ^§Chercheur agréé à l'Institut interuniversitaire des Sciences Nucléaires, Bruxelles, Belgium.