Evidence for aC12+C

Abstract

Excitation functions of the reaction 12 C( 12 C,/>) 23 Na reveal a distinct set of resonances in the # + , f + , (f + ), and (# + ) members of the 23 Na Jfi C l r = -| + ground-state band near E x ( u Ug) = 25.2, 28.2, and 33.3 MeV. These plus earlier data suggest the possible existence of an excited collective band in 24 Mg with very high deformation and large 12 C + 12 C width.

Investigation of high spin states in23Na and23Mg and the12C+12C resonance atE c.m.=19.3 MeV

“…The proton cross sections at 0~b=7.5 ~ [2] are similar to the neutron ones. So the total decay cross sections of the resonance to 23Mg…”

“…The total width F is about 600 keV obtained from the 12C(12C, p) [2] and 12C(12C, n) excitation functions.…”

“…By bombarding 12C with 12C it was recently observed that especially the 9.81MeV state in 23Na is resonantly excited also at lower incident energies (E .... = 11.4 and 14.3 MeV). These resonances correspond to possibly 8 + and 10 + states in the compound system [2]. Even at the 8 + resonance no resonant population of the 13/2 + and lower spin members of the g.s.…”

“…During the last years increasing interest was focussed on the decay of the 19.3 MeV resonance in the 12C + 12C system [1][2][3][4][5][6][7][8][9] which first had been observed by its proton [1] and a little bit later by its neutron decay [8]. The nature of the resonance is still an open question.…”

Clustering aspects in N = Z nucleus 24Mg studied by antisymmetized molecular dynamics

“…According to the Ikeda's diagram [3], a couple of threshold energies that decompose the system into clusters such as 12 C+ 12 C, α+ 20 Ne and 2α+ 16 O are located at approximately 10 to 20 MeV in excitation energy. Cluster model studies [4,5,6,7] have been devoted to reveal them, but to date, little is known and their existence has not been established well, except for the well-known 12 C+ 12 C molecular resonances [8,9,10]. It is also noted that very recently Girod and Schuck [11] have pointed out the possible existence of 6α cluster state around 30 MeV based on the Hartree-FockBogoliubov (HFB) calculation.…”