Abstrakt
We suggest a generalized method for elimination of spurious admixtures (SA) from intrinsic nuclear excitations described within the quasiparticle random-phase approximation (QRPA). Various kinds of SA corrections are treated at the same theoretical ground.
The known corrections are well reproduced. As relevant cases, we consider subtraction of SA related with (i) violation of the translational invariance (isovector E1 and isoscalar toroidal and compression E1 modes), (ii) pairing-induced nonconservation of the particle number (E2(K = 0) and E0 modes), and (iii) rotational invariance (E2(K = 1) and M1(K = 1) modes).
The SA subtraction can be done at the level of QRPA states, electromagnetic responses, and even transition operators. The additional deformation-induced corrections for El excitations are proposed and shown to be essential for the compression isoscalar mode.
The accuracy of the method is demonstrated by Skyrme QRPA calculations for axially deformed Sm-154.