Insights into the mechanisms and time-scales of breakup of 6,7Li

• Published in: Physics letters. B Vol. 695; no. 1-4; pp. 105 - 109
• Main Authors: Luong, D.H., Dasgupta, M., Hinde, D.J., Rietz, R. du, Rafiei, R., Lin, C.J., Evers, M., Diaz-Torres, A.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 10.01.2011; Elsevier
• Subjects: Exact sciences and technology; Exclusive breakup; Fusion; Nuclear clusters; Nuclear physics; Physics; The physics of elementary particles and fields; Transfer-breakup; Weakly-bound nuclei; Exclusive breakup; Weakly-bound nuclei; Transfer-breakup; Fusion; Nuclear clusters; Protons; Neutrons; Models; Excitation; Energy barrier; Dectector arrays
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2010.11.007

Using a back-angle detector array covering 117° to 167°, coincidence measurements of breakup fragments at sub-barrier energies have enabled the complete characterisation of the breakup processes in the reactions of 6,7Li with 208Pb. Those breakup processes fast enough (∼10−22 s) to affect fusion are identified through the measured relative energy of the two breakup fragments. The majority of these prompt breakup events are triggered by transfer of a neutron from 6Li, and of a proton to 7Li. These mechanisms, rather than breakup following direct projectile excitation, should thus be responsible for the majority of the ∼30% suppression of complete fusion observed at above-barrier energies. Breakup characteristics thus depend both on the properties of the initial nucleus and its neighbours. Quantitative modelling of this two-step process will require development of a complete reactions model, relevant for reactions involving both α-cluster nuclei, and exotic nuclei near the neutron and proton drip-lines.