Seniority-conserving forces and USp„2j¿1... partial dynamical symmetry
نویسندگان
چکیده
A quasispin tensor decomposition of the two-nucleon interaction determines the most general seniorityconserving rotationally invariant two-body interaction in a j shell. Such interactions define solvable and partially solvable shell model Hamiltonians for which the unitary symplectic algebra USp(2 j11) provides a complete set of quantum numbers for a subset of states. The matrix elements of seniority-conserving interactions are deduced from the matrix elements of USp(2 j11) operators. A new and powerful numerical technique is presented for computing irreps of the USp(2 j11) algebra. Applications are reported for the lowenergy spectra of N550 and N5126 isotones. The effects of including seniority nonconserving interactions are investigated.
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