Eur. Phys. J. A (2007) 31: 279-302
https://doi.org/10.1140/epja/i2006-10275-5

Regular Article - Nuclear Structure and Reactions

Spectroscopy of ¹⁷C and (sd )³ structures in heavy carbon isotopes

¹ Hahn-Meitner-Institut Berlin, Glienicker Strasse 100, D-14109, Berlin, Germany
² Flerov Laboratory of Nuclear Reactions, JINR, RU-141980, Dubna, Russia
³ Institute for Nuclear Research and Nuclear Energy, BAS, Blvd. Tsarigradsko Shosse 72, BG-1784, Sofia, Bulgaria
⁴ Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, D-14195, Berlin, Germany
⁵ Department of Physics and Astronomy, Ohio University, 45701-2979, Athens, OH, USA
⁶ IGNP, RCC Kurchatov Institute, Kurchatov Square 1, RU-123182, Moscow, Russia
⁷ INFN, Laboratori Nazionali di Legnaro, I-35020, Legnaro, Italy
⁸ Rud height 0.09ex width 0.315emer Bošković Institute, Bijenicka 54, HR-10002, Zagreb, Croatia

Received: 19 February 2007
Accepted: 20 February 2007
Published online: 12 March 2007

Abstract

The structure of ¹⁷C has been investigated using the three-neutron transfer reaction (¹²C,⁹C) on a ¹⁴C target at 231MeV incident energy, the reaction Q-value is Q ₀ = - 46.930MeV. Eleven new states up to 16.3MeV excitation energy were identified. The same reaction has also been used on a ¹²C target ( Q ₀ = - 38.787MeV), and excited states in ¹⁵C up to 19MeV were observed. In ¹⁷C the three transferred neutrons populate (sd )³ configurations on the ¹⁴C core. The comparison of levels populated by the (¹²C,⁹C) reaction in ¹⁷C, ¹⁶C and ¹⁵C reveals a strong similarity of their properties. This concerns especially nine states in each of the three carbon isotopes, which show practically the same excitation energies except a constant mean shift of +5.82MeV for ¹⁶C and +6.65MeV for ¹⁵C with respect to ¹⁷C. The triples of states from the three isotopes, which correspond to each other, have also similar widths and cross-section ratios. It is concluded that the same (sd )³ structures are populated in the three carbon isotopes. The observed levels of ¹⁷C are also compared to the levels of ¹⁹O with known assignments and to shell model calculations, and their decay properties are discussed.