Open Access

Aldric Revel, F. M. Marqués, Olivier Sorlin, Thomas Aumann, Christoph Caesar, Matthias Holl, Valerii Panin, Marine Vandebrouck, Felix Wamers, Héctor Álvarez Pol, Leyla Atar, Vladimir Avdeichikov, Saul Beceiro-Novo, Daniel Bemmerer, Jose Fernando Benlliure Anaya, Carlos A. Bertulani, Juan Manuel Boillos Betete, Konstanze Boretzky, Maria José Garcia Borge, Manuel Caamaño, Enrique Casarejos Ruiz, Wilton N. Catford, Joakim Cederkäll, Marielle Chartier, Leonid V. Chulkov, Dolores Cortina Gil, Edgar Cravo, Raquel Crespo, Ushasi Datta Pramanik, P. Dı́az Fernández, Iris Dillmann, Zoltán Elekes, Joachim Enders, Olga Ershova, Alfredo Estradé Vaz, Fabio Farinon, Luis Mario Fraile Prieto, Martin Freer, Daniel Galaviz Redondo, Hans Geissel, Roman Gernhäuser, Pavel Golubev, Kathrin Göbel, Julius Hagdahl, Tanja Heftrich, Michael Heil, Marcel Heine, Andreas Heinz, Ana Henriques, Alexander Ignatov, Håkan T. Johansson, Björn Jonson, Julian Kahlbow, Nasser Kalantar-Nayestanaki, Rituparna Kanungo, Aleksandra Kelic-Heil, Alexander Knyazev, Thorsten Kröll, Nikolaus Kurz, Marc Labiche, Christoph Langer, Tudi Le Bleis, Roy Crawford Lemmon, Simon Lindberg, Jorge Machado, Justyna Marganiec, Alina Movsesyan, Enrique Nácher González, Mohammad Ali Najafi, Thomas Nilsson, Chiara Nociforo, Stefanos Paschalis, Angel Perea Martinez, Marina Petri, Stephane Pietri, Ralf Plag, René Reifarth, Guillermo Ribeiro Jimenez, Catherine Rigollet, Marko Röder, Dominic M. Rossi, Deniz Savran, Heiko Scheit, Haik Simon, Ina Syndikus, Jonathan Thomas Taylor, Olof Tengblad, Ronja Thies, Yasuhiro Togano, Paulo Velho, Vasily Volkov, A. Wagner, Helmut Weick, Carl Wheldon, Gemma Louise Wilson, John S. Winfield, Philip John Woods, Dmitry Yakorev, Mikhail V. Zhukov, Andreas Zilges, Kai Zuber

• The emission of neutron pairs from the neutron-rich N 1⁄4 12 isotones 18C and 20O has been studied by high-energy nucleon knockout from 19N and 21O secondary beams, populating unbound states of the two isotones up to 15 MeV above their two-neutron emission thresholds. The analysis of triple fragment-n-n correlations shows that the decay 19Nð−1pÞ18C* → 16C þ n þ n is clearly dominated by direct pair emission. The two-neutron correlation strength, the largest ever observed, suggests the predominance of a 14C core surrounded by four valence neutrons arranged in strongly correlated pairs. On the other hand, a significant competition of a sequential branch is found in the decay 21Oð−1nÞ20O* → 18O þ n þ n, attributed to its formation through the knockout of a deeply bound neutron that breaks the 16O core and reduces the number of pairs.