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Physical Review C, Nuclear Physics

Publication date: 2010-02-04
Volume: 81
Publisher: Published for the American Physical Society by the American Institute of Physics

Author:

Hyldegaard, S
Alcorta, M ; Bastin, Beyhan ; Borge, MJG ; Boutami, R ; Brandenburg, S ; Büscher, Jeroen ; Dendooven, P ; Diget, C Aa ; Van Duppen, Piet ; Eronen, T ; Fox, SP ; Fraile, LM ; Fulton, BR ; Fynbo, HOU ; Huikari, J ; Huyse, Marc ; Jeppesen, HB ; Jokinen, AS ; Jonson, B ; Jungmann, K ; Kankainen, A ; Kirsebom, OS ; Madurga, M ; Moore, I ; Nieminen, A ; Nilsson, T ; Nyman, G ; Onderwater, GJG ; Pentila, H ; Perajarvi, K ; Raabe, Riccardo ; Riisager, K ; Rinta-Antila, S ; Rogachevskiy, A ; Sastamoinen, A ; Sohani, M ; Tengblad, O ; Traykov, E ; Wang, Y ; Wilhemsen, K ; Wilschut, HW ; Aysto, J

Keywords:

Science & Technology, Physical Sciences, Physics, Nuclear, Physics, ALPHA-PARTICLES, EXCITED-STATES, 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics, Nuclear & Particles Physics, 5106 Nuclear and plasma physics

Abstract:

The β decays of 12N and 12B have been studied at KVI and JYFL to resolve the composition of the broad and interfering 0+ and 2+ strengths in the triple-α continuum. For the first time a complete treatment of 3α decay is presented including all major breakup channels. A multilevel, many-channel R-matrix formalism has been developed for the complete description of the breakup in combination with the recently published separate analysis of angular correlations. We find that, in addition to the Hoyle state at 7.65 MeV, more than one 0+ and 2+ state is needed to reproduce the spectra. Broad 0+_3 and 2+_2 states are found between 10.5 and 12 MeV in this work. The presence of β strength up to the 12N Q-value window suggests the presence of additional 0+ and 2+ components in the 12C structure at energies above 12.7 MeV.