The momentum distribution of projectile fragments from the breakup of light exotic nuclei

The momentum distribution of projectile fragments produced from the breakup of β - unstable nuclei was studied, and we have tried to extract the information on the single particle wave function of valence nucleon(s) from the momentum distribution. For the two-neutron-removal process from 6,8 He and 9,11 Li, the momentum distribution of the projectile-rapidity neutron showed that the main reaction mechanism is the two-step process via the intermediate resonance. In such cases, the momentum distribution is determined by the properties of the resonance rather than the initial nuclei. For understanding the single-particle wave function of valence neutrons in such halo nuclei, it is necessary to develop other type of experimental technique. For the one-neutron-removal process from 11 Be, the single-particle wave function in a Woods Saxon potential reproduced well the observed momentum distribution, if the separation energy is treated properly. This method provides a nice experimental tool to study the nucleus with a single halo neutron. For the one-proton-removal process from 8 B, 9 C, and 13 O, the calculated momentum distribution for 8 B and 9 C was wider then the experimental distribution. The reason of this is not clear at the moment. (author)