Speaker
Description
The double Gamow–Teller (DGT) transition is a nuclear process such that both of the spin and isospin are flipped twice without changing the orbital angular momentum. The nuclear response of the DGT transition is hardly known especially in the high excitation energy region. The existence of giant resonance in DGT transition, DGT giant resonance (DGTGR), is expected. The experimental observables of the DGTGR will provide the information about the two-phonon excitation in which the spin-degrees of freedom contribute. It is also important in the connection to the nuclear matrix element of neutrino-less double $\beta$ decay.
The first experiment using the double charge exchange reaction of ($^{12}{\rm C}, ^{12}{\rm Be}(0^{+}_{2})$) at RIBF was performed in 2021, aiming at the observation of the DGTGR. We measured for the $^{48}{\rm Ca}$ target with primary beam of $^{12}{\rm C}$ with the energy of 250 MeV/nucleon. We obtained the excitation energy distribution of the double differential cross section with the resolution of 1.5 MeV. The forward-peaking structure was observed at around 20 MeV in the excitation energy in $^{48}{\rm Ti}$. The integrated $0^{\circ}$ cross section below 34 MeV is 1.33$\pm$0.12 $\mu$b/sr.
In order to extract the DGT components, the experimental angular distributions were compared with the calculated one. The extracted DGT strength below 34 MeV is $22^{+17}_{-6}$% of the sum rule value.
In this contribution, we will report the outline of the experiment and the analysis.
| Type of contribution | poster |
|---|---|
| Are you a student or postdoc? | yes |
