Contribution Of The 2p1h And 3p1h Vertex Operation To The Spectra Of Double-particle About Double Closed Shell

Content: Using the method of Green's function and partial summation of multi- ple scattering,we have investigated in various approximations the contribution of 2p1h multiple scattering and 3p1h multiple scattering to the double-particle en- ergy spectras of Ca⁴²,Sc⁴²,Ni⁵⁸ andCu⁵⁸ respectively.In our caculation,we use the matrix elements of M-3Y force as the equivalent G-matrix elements introduced by Bertsch and the energy dependence on G matrices has been taken into account rigorously.And the harmonic oscillator potential is taken as a good approximation of the average field,so the harmonic wave function is used as the single particle wave function.As a important step,we have considered an approximation for the M_{αα′ββ′}, up to the second order and 2p1h multiple scattering and 3p1h multiple scattering correlation are taken into account.Therefore,we can include much more diagrams in our works.The spectras including the multiple scattering agree with the experiment fairly well,especially in the spectra of Ca⁴².There is an improve- ment in the spectra of Ni⁵⁸ compared with the previous results which is obtained with Hamada-Johnston interaction,the Yale and Reid free nucloen-nucloen poten- tials.In this work,the reverse order energy-level is solved.Considering the multiple scattering in the second interaction of 2p1h or 3p1h diagram,some energy-levels are heightened,others are descened, which made the calculated results agree with the observed datas.The results also show that the matrix elements of M-3Y force as the equivalent G-matrix elements are suitable for calculation of the nuclear in this region.