Семинар «Ядерная физика низких энергий»

Дата и время: пятница, 16 апреля 2021 г., в 14:30

Место: Онлайн-конференция в Zoom, Лаборатория теоретической физики им. Н.Н. Боголюбова

Ссылка для подключения

Тема семинара: «First calculation of double-gamma decay width of a nuclear 2_1⁺ state: The case of ⁴⁸Ca»

Докладчики: А. П. Северюхин¹, Н. Н. Арсеньев¹, Н. Пьетралла^2
1 — Лаборатория теоретической физики им. Н.Н.Боголюбова, Объединенный институт ядерных исследований
² — Институт ядерной физики Общества Макса Планка, Дармштадтский технический университет

Аннотация:

The competitive double-gamma decay of the 2_1⁺ state of an even-even spherical nucleus is studied for the first time. The coupling between one-, two- and three-phonon terms in the wave functions of excited states is taken into account within the microscopic model based on the Skyrme energy density functional. The approach enables one to perform the calculations in very large configurational spaces. It is shown that the double-gamma decay width is sensitive to the energy difference of the one-phonon doorway mode and the two-phonon structure which arises from the coupling of this doorway to the low-energy phonons. It is further correlated to the strength of the phonon-phonon coupling. The maximal branching ratio of the competitive double-gamma decay relative to its single gamma-decay is predicted for ⁴⁸Ca as 3*10^-8. It is desirable to experimentally establish the double-gamma decay of a first 2⁺ state of an even-even nucleus.