U(6/20) supersymmetry in 115-119Sn isotopes.

Abstract

In this paper we have studied the low energy structure of $^{115--119}\mathrm{Sn}$ isotopes within the vibrational limit for bosons under ${\mathrm{U}}^{\mathit{BF}}$(5)\ensuremath{\bigotimes}${\mathrm{SU}}^{\mathit{F}}$(4) dynamical symmetry of the graded Lie group U(6/20). Calculation of excitation energy spectra of positive parity levels and B(E2) values of these isotopes has been performed using this dynamical symmetry. Comparison of experimental and calculated energy spectra and B(E2) values of these nuclei suggests the existence of an approximate U(6/20) supersymmetry in these isotopes. \textcopyright{} 1996 The American Physical Society.