Hints of quasi-molecular states in 13B via the study of 9Li-4He elastic scattering

Abstract

This paper reports on elastic scattering excitation functions for the reaction 9Li+4He measured at backward angles in the centre of mass energy range 5 MeV ≤ Ec.m. ≤ 9.5 MeV, with the aim of investigating the possible existence of molecular resonances which have been predicted to exist in the case of neutron-rich B-isotopes. Due to the short lifetime of 9Li, the experiment necessitated the use of inverse kinematics on a gaseous 4He target. The Thick Target Inverse Kinematics technique was used which allowed for the measurement of the full excitation function in a single 9Li run. Broad resonances were observed in the excitation region for 13B 15 MeV ≤ Ex ≤20 MeV. To understand the nature of such broad structures, various theoretical attempts are reported concerning possible reaction mechanisms for this neutron rich reaction. The most promising approach to interpret the data is within the orbiting reaction scenario.