Precise measurement of the ${\hat{I}}^3$-decay probability of the Hoyle state with a new triple coincidence-detection method

Abstract

We measured the ${\hat{I}}^3$-decay probability of the Hoyle state with a new method of triple coincidence detection of a scattered $\hat{I}\pm$ particle, a recoil ${}^{12}\mathrm{C}$ nucleus, and a ${\hat{I}}^3$ ray in inelastic alpha scattering on ${}^{12}\mathrm{C}$. This method successfully enabled a low-background measurement and a precise determination of the ${\hat{I}}^3$-decay probability of the Hoyle state as $\hat{I}{“}_{\hat{\mathrm{I}}}^3/\hat{I}“=[4.00\pm 0.22(sta.)\pm 0.18(sys.)]\times 10^{-4}$, which is consistent with the previous literature value. Therefore, we concluded that the literature value can be reliably used in the study of nucleosynthesis in the universe.

8 pages, 8 figures