학술논문
Measurement of the Isolated Nuclear Two-Photon Decay in $^{72}\mathrm{Ge}$
Document Type
Working Paper
Author
Freire-Fernández, D.; Korten, W.; Chen, R. J.; Litvinov, S.; Litvinov, Yu. A.; Sanjari, M. S.; Weick, H.; Akinci, F. C.; Albers, H. M.; Armstrong, M.; Banerjee, A.; Blaum, K.; Brandau, C.; Brown, B. A.; Bruno, C. G.; Carroll, J. J.; Chen, X.; Chiara, Ch. J.; Cortes, M. L.; Dellmann, S. F.; Dillmann, I.; Dmytriiev, D.; Forstner, O.; Geissel, H.; Glorius, J.; Görgen, A.; Górska, M.; Griffin, C. J.; Gumberidze, A.; Harayama, S.; Hess, R.; Hubbard, N.; Ide, K. E.; John, Ph. R.; Joseph, R.; Jurado, B.; Kalaydjieva, D.; Kanika, K.; Kondev, F. G.; Koseoglou, P.; Kosir, G.; Kozhuharov, Ch.; Kulikov, I.; Leckenby, G.; Lorenz, B.; Marsh, J.; Mistry, A.; Ozawa, A.; Pietralla, N.; Podolyák, Zs.; Polettini, M.; Sguazzin, M.; Sidhu, R. S.; Steck, M.; Stöhlker, Th.; Swartz, J. A.; Vesic, J.; Walker, P. M.; Yamaguchi, T.; Zidarova, R.
Source
Subject
Language
Abstract
The nuclear two-photon or double-gamma ($2\gamma$) decay is a second-order electromagnetic process whereby a nucleus in an excited state emits two gamma rays simultaneously. To be able to directly measure the $2\gamma$ decay rate in the low-energy regime below the electron-positron pair-creation threshold, we combined the isochronous mode of a storage ring with Schottky resonant cavities. The newly developed technique can be applied to isomers with excitation energies down to $\sim100$\,keV and half-lives as short as $\sim10$\,ms. The half-life for the $2\gamma$ decay of the first-excited $0^+$ state in bare $^{72}\mathrm{Ge}$ ions was determined to be $23.9\left(6\right)$\,ms, which strongly deviates from expectations.
Comment: Submitted to Physical Review Letters, 8 pages, 3 figures, 2 tables, 7 equations
Comment: Submitted to Physical Review Letters, 8 pages, 3 figures, 2 tables, 7 equations