Comparison between optical-model potentials in G-matrix folding method and improved local-density approximation method

Microscopic optical-model potentials evaluated by two methods in a nuclear matter approach, namely a $G$-matrix folding method and an improved local-density approximation (LDA) method, are compared. The real parts agree well and show good correspondence to a phenomenological Woods-Saxon potential when second-order contributions are taken into account. On the other hand, the resemblance is not so good in an imaginary part. The reason for the similarity in the real part of the two methods is examined. The improved LDA, which requires less numerical effort, is useful to apply in other cases such as hyperon potentials.