MOMENTUM DISTRIBUTIONS OF A LI-9 FRAGMENT ARISING FROM THE (LI-11, LI-9) REACTION AND NEUTRON CORRELATIONS

The inclusive momentum distribution of a Li-9 fragment arising from the (Li-11, Li-9) reaction on light target nuclei at an incident energy of 800 MeV/nucleon is calculated within the Glauber theory. Both the reaction dynamics and the two-neutron correlation in the Li-11 ground-state wave function is taken into account. The momentum distribution is found to reflect precisely the motion of the halo neutrons and affected little by the reaction dynamics. Some simple wave functions are employed to investigate the sensitivity of the momentum distribution to the structure of the halo neutrons. Neither the simple shell model nor the di-neutron cluster model alone reproduces the measured distribution. A linear combination of the shell-model and di-neutron cluster-model wave functions is found to reproduce the measured distribution, where the interference between them plays the important role in producing both narrow and wide components of the distribution.