Probing transfer to unbound states of the ejectile with weakly bound 7Li on 93Nb

TL;DR

This study investigates transfer and breakup processes in the $^7$Li+$^{93}$Nb reaction near the Coulomb barrier, revealing transfer to unbound states of the ejectile through experimental data and theoretical models.

Contribution

It provides detailed experimental data and theoretical analysis demonstrating transfer to unbound states of $^7$Li in the reaction with $^{93}$Nb, a novel insight into reaction mechanisms.

Findings

Transfer to unbound states confirmed by data and models

$ ext{α}+ ext{α}$ events are less frequent than $ ext{α}+ ext{d}$ and $ ext{α}+ ext{t}$ events

Theoretical calculations support direct transfer to unbound states as the main process.

Abstract

The two-step process of transfer followed by breakup is explored by measuring a rather complete set of exclusive data for reaction channels populating states in the ejectile continua of the $^7$Li+$^{93}$Nb system at energies close to the Coulomb barrier. The cross sections for $\alpha+\alpha$ events from one proton pickup were found to be smaller than those for $\alpha+d$ events from one neutron stripping and $\alpha+t$ events from direct breakup of $^7$Li. Coupled channels Born approximation and continuum discretized coupled channels calculations describe the data well and support the conclusion that the $\alpha+d$ and $\alpha+\alpha$ events are produced by direct transfer to unbound states of the ejectile.