Conventional coupled-channels analyses, that take account of only the collective excitations of the colliding nuclei, have failed to reproduce the different behavior of the experimental quasi-elastic barrier distributions for the 20Ne+90,92Zr systems. To clarify the origins of this difference, we investigate the effect of noncollective excitations of the Zr isotopes. Describing these excitations in a random-matrix model, we explicitly take them into account in our coupled-channels calculations. The noncollective excitations are capable of reproducing the observed smearing of the peak structure in the barrier distribution for 20Ne+92Zr, while not significantly altering the structure observed in the 20Ne+90Zr system. The difference is essentially related to the closed neutron shell in 90Zr.
ASJC Scopus subject areas
- Nuclear and High Energy Physics