Speaker
Mr
Ryan Dunlop
(University of Guelph)
Description
Half-lives of $N=82$ nuclei below doubly-magic $^{132}$Sn are key input parameters for calculations of any astrophysical $r$-process scenario and play an important role in the formation and shape of the second $r$-process abundance peak. In the past, shell-model calculations of neutron-rich nuclei near the $N=82$ neutron shell closure that are not yet experimentally accessible have been performed by adjusting the quenching of the Gamow-Teller (GT) operator to reproduce the half-life of $^{130}$Cd [1]. The calculated half-lives of other nuclei in the region are known to be systematically too long. Recently, a shorter half-life for $^{130}$Cd was reported [2,3]. A re-scaling of the GT quenching to the new $^{130}$Cd half-life by a constant factor resolved the discrepancy [2,3]. However, this GT rescaling creates a new discrepancy in the calculated half-life of $^{131}$In.
The half-life measurement of $^{131}$In is complicated due to the presence of three known $\beta$-decaying states with similar half-lives, making photopeak gating an ideal method to measure each of these half-lives. In this talk, the half-lives of $^{130}$Cd and $^{131}$In, as well as the spectroscopy of the $\beta$ and $\beta-n$ decay of $^{131}$In measured using the GRIFFIN $\gamma$-ray spectrometer at TRIUMF will be presented.
[1] M. Hannawald $\textit{et al.}$, Nucl. Phys. A $\textbf{688}$, 578 (2001)
[2] R. Dunlop $\textit{et al.}$, Phys. Rev. C $\textbf{93}$, 062801(R) (2016)
[3] G. Lorusso $\textit{et al.}$, Phys. Rev. Lett. $\textbf{114}$, 192501 (2015)
| [email protected] | |
| Collaboration name | GRIFFIN Collaboration |
Primary author
Mr
Ryan Dunlop
(University of Guelph)
