Particularly an analytical expression for the longitudinal momentum distribution is derived if the density distribution of halo nucleons is assumed as a gaussian type function . a direct connection of the width of the momentum distribution to the bound state wave function of halo nucleons is established 特别是在晕核子的纵向和横向密度分布可分离的情况下,如高斯密度分布,进一步求解了纵向动量分布宽度的解析形式,建立了分布宽度与晕核子束缚态波函数之间的直接联系。