Institution: | (1) Institut für Strahlen- und Kernphysik, Univ. Bonn, W.-Germany;(2) Centre de Recherches Nucléaires, Strasbourg, France;(3) Present address: Tata Institute of Fundamental Research, Bombay, India;(4) Present address: The Coimbra University, Coimbra, Portugal;(5) Present address: Weizmann Institute of Science, Rehovot, Israel |