We derive a theoretical method for calculating the averages (over J and T) of matrix elements of the nuclear effective interaction, in any order of the linked cluster expansion. We apply this to calculate all terms through fourth order in the G-matrix, for the averages in mass-6 and mass-18 nuclei. We find that the averages in fourth order are as large as in second and third order. This behavior is associated with a small number of terms, which suggests a partial summation method of improving the series. The relation to other work is discussed.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics