Investigation of the reaction 12C(7Li, t)16O

Cluster structure of 13C probed via the 7Li(9Be,9Be+α) reaction

“…Typically, the ( 7 Li,t) angular distributions are less oscillatory than those for the ( 6 Li,d) reaction, and are reminiscent of those that appear in Figure 3. The reduced structure in the ( 7 Li,t) angular distributions is related to the presence of two transfer angular momentum values, L, for each L f [15,16], for L f >0. Nevertheless, the compilation of the α-transfer reaction in [15] indicates the sensitivity to the orbital angular momentum of the orbit into which the α-particle is transferred.…”

“…Correspondingly, this picture would suggest that the 8 Be ground state should possess an α-α cluster structure, and the 3α cluster structure should appear at an excitation energy close to 7.3 MeV in 12 C. Indeed, it has been recently speculated that certain states above the 3α decay threshold in 12 C (e.g. the 7.65 MeV state), or the 4α decay threshold in 16 O, should possess properties reminiscent of a Bose gas [2].…”

The α-12C scattering studied via the Trojan-Horse method

“…The 6 Li nucleus has been chosen as the trojan horse because the ground state is l = 0, which makes the application of the method simpler. The Fourier transform of the ground state wave function is well known and peaks at zero momentum which determines the quasi-free scattering angles.…”

“…Od is a kinematic factor, which can be calculated from the experimental conditions; b) |χ Li (p d )| 2 is the deuteron momentum distribution in 6 Li, which depends only on the internal wave function and is in principle independent of the experimental conditions; because of the impulse approximation, the momentum of the (spectator) deuteron in its final state is considered to be the same as its initial momentum in 6 Li; c) dσ dΩαC is the two-body differential scattering cross section for the α-12 C sub-system which is assumed to be on-shell in the quasi-free approximation.…”

“…In the PWBA the last factor is not directly the on-shell 2-body cross section, but a more complicated expression containing the 2-body cross section but also incorporating the fact that the 2-body process does not take place on-shell, since the α-particle is initially bound in 6 Li.…”