Speaker
Dr
Tomohiro Uesaka
(RIKEN)
Description
In a long history of nuclear physics, double Gamow-Teller responses have been
hardly studied, at least experimentally. Existing data include half-lives of only ~10 double beta nuclei. This exhibits a striking contrast to the case of single Gamow-Teller responses where data of half-lives exist for more than 2000 nuclides together with cross section data of charge exchange reactions.
One possible way to access double Gamow-Teller responses in nuclei other than double beta-decay ones and to the excited states is to use double charge exchange reactions. However, previous attempts with pion and heavy-ion double charge exchange reactions provided us with limited information.
We started a new experimental program to investigate double Gamow-Teller responses in a wide excitation energy range with a newly invented experimental method to use the (12C,12Beγ) reaction. One of the highlight of the program is a discovery of the double Gamow-Teller giant resonances that exhaust a major part of the sum-rule value. The first experiment was carried out with a 100-MeV 12C beam at Research Center for Nuclear Physics (RCNP), Osaka University. We have found indication of the double Gamow-Teller giant resonances in 48Ca which is among double beta-decay nuclei. We plan high-statistics experiments with a high intensity 12C beam at RI Beam Factory (RIBF) which will be scheduled in 2019.
In the symposium, I will present results of the RCNP experiment and show future plans at RIBF, after brief introduction to nuclear double Gamow-Teller responses and its relevances to double beta-decay physics.
Primary author
Dr
Tomohiro Uesaka
(RIKEN)
