Preface Giacomo de Angelis, Andrés Gadea, Silvia M. Lenzi, Santo Lunardi, Roberto Menegazzo and Daniel R. Napoli Eur. Phys. J. A, 20 1 (2004) A13-A14 Published online: 15 April 2004 DOI: 10.1140/epja/i2004-10002-4