Fitting Single Particle Energies in sdgh Major Shell

We have performed two kinds of non-linear fitting procedures to the single-particle energies in the sdgh major shell to obtain better shell model results. The low-lying energy eigenvalues of the light Sn isotopes with A = 103−110 in the sdgh-shell are calculated in the framework of the nuclear shell model by using CD-Bonn two-body effective nucleon-nucleon interaction. The obtained energy eigenvalues are fitted to the corresponding experimental values by using two different non-linear fitting procedures, i.e., downhill simplex method and clonal selection method. The unknown single-particle energies of the states 2s_1/2, 1d_3/2, and 0h_11/2 are used in the fitting methods to obtain better spectra of the ^{104,106,108,110}Sn isotopes. We compare the energy spectra of the ^{104,106,108,110}Sn and ^{103,105,107,109}Sn isotopes with/without a nonlinear fit to the experimental results. (nuclear physics)