Abstract
The 12 C + 12 C → 12 C g. s. + α + 8 Be g.s. reaction has been investigated by 12C-α coincidence measurements at incident energies of 90, 110 and 140 MeV. Cross sections of three kinds of intermediate channels ( 12C + 12C ∗, 16O ∗ + 8Be and α + 20Ne ∗) and of non-resonant parts (breakup, etc.) leading to the same 12C g.s. + α + 8Be g.s. final channel have been deduced. Among them the 16O ∗ + 8Be and 12C + 12C ∗ channels had dominant cross sections, whereas massive-cluster transfer (α + 20Ne ∗) and non-resonant reactions contributed only a few percent. For the 16O ∗ + 8Be and 12C + 12C ∗ channels, states in 16O(4 + 1, 5 − 1, 6 1 + and 7 1 −) and in 12C(3 1 − and 4 1 +) were populated selectively. Coincidence cross sections for these channels were reproduced by DWBA calculations. In the present reaction, there are kinematical regions where two intermediate channels 16O ∗ + 8Be and 12C + 12C ∗ can participate at the same time, since these intermediate channels lead to the same final channel, 12C g.s. + α + 8Be g.s.. Cross sections obtained experimentally at such regions could not be explained by a simple sum of the cross sections estimated individually for these two intermediate channels. This shows evidence of interference between two different intermediate channels. The interference effect is discussed in terms of DWBA calculations taking into account interference between T-matrices of the two channels.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call