Breakdown of the $N=8$ magic number near the neutron drip line from parallel momentum distribution analyses

By using two theoretical models (the postform finite range distorted wave Born approximation and the adiabatic model) we calculate the parallel momentum distribution of the charged core in the Coulomb breakup of Be isotopes on a heavy target at 100 MeV/nucleon. We show that the full width at half maxima of the parallel momentum distribution can be used to study the breakdown of the $N=8$ magic number away from the valley of stability.

Figure 1

FWHM of PMD of charged fragment, calculated in the Coulomb breakup of various Be isotopes plotted with respect to neutron number $N$. The triangles and squares are results of FRDWBA and AD calculations, respectively. The lines (solid and dashed) are a guide to the eye. Among the Be isotopes, ${}^{10}\mathrm{Be}$ ($N=6$) has the highest FWHM.