Eur. Phys. J. A (2003) 18: 583-587
https://doi.org/10.1140/epja/i2003-10097-y

Short Note

Excitation of ⁶ Li above the breakup threshold in the ⁶ Li + ²⁰⁸ Pb system around the Coulomb barrier

¹ Physics Department of the University and INFN, via Marzolo 8, 35131, Padua, Italy
² Physics Department of the University and INFN, Udine, via delle Scienze 208, 33100, Udine, Italy
³ University of Surrey, GU27XH, Guilford, UK
⁴ Laboratori Nazionali di Legnaro, INFN, via Romea 4, 35020, Legnaro (Padua), Italy
⁵ Physics Department of the University and INFN, via Cinthia, Naples, Italy

^* e-mail: signorini@pd.infn.it

Received: 2 June 2003
Published online: 18 November 2003

Abstract

The excitation energy above the breakup threshold of the Li system, after the interaction of ⁶Li nuclei with a ²⁰⁸Pb target, was deduced from the invariant mass of the system. Data were collected with a large-solid-angle detector set-up at four beam energies around the Coulomb barrier. The excitation of the ⁶Li nucleus above the breakup threshold (1.47 MeV) has a quite similar behavior at each measured beam energy and angle; it is peaked at MeV above the threshold and shows an exponential decay on the high energy side, which is a clear signature of a direct breakup process. The experimental excitation energies are reproduced both in shape and absolute value by 1) fully quantum-mechanical Coupled-Channel calculations with coupling to discretized-continuum ⁶Li excitations, 2) semi-classical Coupled-Channel approach, where the relative motion is treated along a classical trajectory.