Low-Energy Nuclear Physics Seminar

Date and Time: Friday, 16 April 2021, at 2:30 PM

Venue: Online conference in Zoom, Bogoliubov Laboratory of Theoretical Physics

Link to join the seminar

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

Speakers: A. P. Severyukhin¹, N. N. Arsenyev¹, N. Pietralla^2
1 – Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research
² – Institut für Kernphysik, Technische Universität Darmstadt

Abstract:

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.