Deep sub-threshold Ξ− production in Ar+KCl reactions at 1.76A GeV

G. Agakishiev, A. Balanda, R. Bassini, D. Belver, A.V. Belyaev, A. Blanco, M. Böhmer, J. L. Boyard, P. Braun-Munzinger, P. Cabanelas, E. Castro, S. Chernenko, T. Christ, M. Destefanis, J. Dı́az, F. Dohrmann, A. Dybczak, T. Eberl, L. Fabbietti, O. V. Fateev, P. Finocchiaro, P. Fonte, J. Friese, I. Fröhlich, T. Galatyuk, J. A. Garzón, R. Gernhäuser, A. Gil, C. Gilardi, M. Golubeva, D. González-Dı́az, F. Guber, T. Hennino, R. Holzmann, I. Iori, A. Ivashkin, M. Jurkovic, B. Kämpfer, K. Kanaki, T. Karavicheva, D. Kirschner, I. Koenig, W. Koenig, B. W. Kolb, R. Kotte, F. Krizek, R. Krücken, W. Kühn, A. Kugler, A. Kurepin, S. Lang, J. S. Lange, K. Lapidus, T. Liu, L. Lopes, M. Lorenz, L. Maier, A. Mangiarotti, J. Markert, V. Metag, B. Michalska, J. Michel, D. Mishra, E. Morinière, J. Mousa, C. Müntz, L. Naumann, J. Otwinowski, Y. C. Pachmayer, M. Palka, Y. Parpottas, V. Pechenov, O. Pechenova, J. Pietraszko, W. Przygoda, B. Ramstein, A. Reshetin, M. Roy-Stephan, A. Rustamov, A. Sadovsky, B. Sailer, P. Salabura, A. Schmah, Yu. G. Sobolev, S. Spataro, B. Spruck, H. Ströbele, J. Stroth, C. Sturm, M. Sudol, A. Tarantola, K. Teilab, P. Tlusty, M. Traxler, R. Trebacz, H. Tsertos, V. Wagner, M. Weber, M. Wisniowski, T. Wojcik, J. Wüstenfeld, S. Yurevich, Y. V. Zanevsky, P. Zhou (HADES collaboration) Istituto Nazionale di Fisica Nucleare Laboratori Nazionali del Sud, 95125 Catania, Italy LIP-Laboratório de Instrumentação e Fı́sica Experimental de Partı́culas , 3004-516 Coimbra, Portugal Smoluchowski Institute of Physics, Jagiellonian University of Cracow, 30-059 Kraków, Poland GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany Institut für Strahlenphysik, Forschungszentrum Dresden-Rossendorf, 01314 Dresden, Germany Joint Institute of Nuclear Research, 141980 Dubna, Russia Institut für Kernphysik, Johann Wolfgang Goethe-Universität, 60438 Frankfurt, Germany II.Physikalisches Institut, Justus Liebig Universität Giessen, 35392 Giessen, Germany Istituto Nazionale di Fisica Nucleare, Sezione di Milano, 20133 Milano, Italy Institute for Nuclear Research, Russian Academy of Science, 117312 Moscow, Russia Physik Department E12, Technische Universität München, 85748 München, Germany Department of Physics, University of Cyprus, 1678 Nicosia, Cyprus Institut de Physique Nucléaire (UMR 8608), CNRS/IN2P3 Université Paris Sud, F-91406 Orsay Cedex, France Nuclear Physics Institute, Academy of Sciences of Czech Republic, 25068 Rez, Czech Republic Departamento de Fı́sica de Partı́culas, Univ. de Santiago de Compostela, 15706 Santiago de Compostela, Spain Instituto de Fı́sica Corpuscular, Universidad de Valencia-CSIC, 46971 Valencia, Spain a also at ISEC Coimbra, Coimbra, Portugal b also at Technische Universität Dresden, 01062 Dresden, Germany c also at Dipartimento di Fisica, Università di Milano, 20133 Milano, Italy d also at Excellence Cluster Universe, Technische Universität München, 85748 Garching, Germany