  Using two theoretical models (the post form 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/u. We show that the full width at half maxima of the
parallel momentum distribution can be used to study the breakdown of N = 8
magic number away from the valley of stability.
