Elimination of spurious modes in quasiparticle random phase approximation


Семинар «Ядерная физика низких энергий»

Дата и время: вторник, 12 февраля 2019 г., в 11:00

Место: Лекционный зал (2-й этаж), Лаборатория теоретической физики им. Н.Н. Боголюбова

Тема семинара: «Elimination of spurious modes in quasiparticle random phase approximation»

Авторы: А. Репко (Физический институт, Словакия), Дж. Квасил (Институт физики частиц и ядерной физики, Чехия), В.О. Нестеренко (ЛТФ ОИЯИ)

Докладчик: А. Репко


Mean-field calculations of ground and excited states of nuclei necessarily involve spontaneous symmetry breaking, which leads to certain artifacts in such calculations. In particular, the excited states, as obtained by Quasiparticle Random Phase Approximation (QRPA), contain one or more spurious modes, whose multipolarity is given by the broken symmetry, e.g. translational (E1), rotational (M1/E2) and particle-number symmetry, which is related to pairing (E0). Although QRPA, in theory, should lead to their complete separation from the physical modes, certain admixtures remain due to the finiteness of the employed configuration space. The talk will focus on the elimination of these admixtures by an universal approach, both before and after QRPA diagonalization. The results will be demonstrated for spherical and axial nuclei.