Beyond the Neutron Drip-Line: The Unbound Oxygen Isotopes 25O and 26O
Abstract
The very neutron-rich oxygen isotopes 25O and 26O are investigated experimentally and theoret- ically. In this first R3B-LAND experiment, the unbound states are populated at GSI via proton- knockout reactions from 26F and 27F at relativistic energies around 450 MeV/nucleon. From the kinematically complete measurement of the decay into 24O plus one or two neutrons, the 25O ground- state energy and lifetime are determined, and upper limits for the 26O ground state are extracted. In addition, the results provide evidence for an excited state in 26O at around 4 MeV. The ex- perimental findings are compared to theoretical shell-model calculations based on chiral two- and three-nucleon (3N) forces, including for the first time residual 3N forces, which are shown to be amplified as valence neutrons are added.
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Cite
@article{arxiv.1209.0156,
title = {Beyond the Neutron Drip-Line: The Unbound Oxygen Isotopes 25O and 26O},
author = {C. Caesar and J. Simonis and T. Adachi and Y. Aksyutina and J. Alcantara and S. Altstadt and H. Alvarez-Pol and N. Ashwood and T. Aumann and V. Avdeichikov and M. Barr and S. Beceiro and D. Bemmerer and J. Benlliure and C. A. Bertulani and K. Boretzky and M. J. G. Borge and G. Burgunder and M. Caamano and E. Casarejos and W. Catford and J. Cederkäll and S. Chakraborty and M. Chartier and L. Chulkov and D. Cortina-Gil and U. Datta Pramanik and P. Diaz Fernandez and I. Dillmann and Z. Elekes and J. Enders and O. Ershova and A. Estrade and F. Farinon and L. M. Fraile and M. Freer and M. Freudenberger and H. O. U. Fynbo and D. Galaviz and H. Geissel and R. Gernhäuser and P. Golubev and D. Gonzalez Diaz and J. Hagdahl and T. Heftrich and M. Heil and M. Heine and A. Heinz and A. Henriques and M. Holl and J. D. Holt and G. Ickert and A. Ignatov and B. Jakobsson and H. T. Johansson and B. Jonson and N. Kalantar-Nayestanaki and R. Kanungo and A. Kelic-Heil and R. Knöbel and T. Kröll and R. Krücken and J. Kurcewicz and M. Labiche and C. Langer and T. Le Bleis and R. Lemmon and O. Lepyoshkina and S. Lindberg and J. Machado and J. Marganiec and V. Maroussov and J. Menéndez and M. Mostazo and A. Movsesyan and A. Najafi and T. Nilsson and C. Nociforo and V. Panin and A. Perea and S. Pietri and R. Plag and A. Prochazka and A. Rahaman and G. Rastrepina and R. Reifarth and G. Ribeiro and M. V. Ricciardi and C. Rigollet and K. Riisager and M. Röder and D. M. Rossi and J. Sanchez del Rio and D. Savran and H. Scheit and A. Schwenk and H. Simon and O. Sorlin and V. Stoica and B. Streicher and J. Taylor and O. Tengblad and S. Terashima and R. Thies and Y. Togano and E. Uberseder and J. Van de Walle and P. Velho and V. Volkov and A. Wagner and F. Wamers and H. Weick and M. Weigand and C. Wheldon and G. Wilson and C. Wimmer and J. S. Winfield and P. Woods and D. Yakorev and M. V. Zhukov and A. Zilges and M. Zoric and K. Zuber and R3B collaboration},
journal= {arXiv preprint arXiv:1209.0156},
year = {2019}
}