Speaker
Description
R. Cavallaro$^{*1,2}$, G. Cardella$^2$, N. S. Martorana$^2$, A. Castoldi$^3$, E. De Filippo$^2$, E. Gambera$^{1,2}$, E. Geraci$^{1,2,4}$, B. Gnoffo$^{1,2}$, C. Guazzoni$^3$, C. Maiolino$^5$, E. V. Pagano$^5$, S. Pirrone$^2$, G. Politi$^{1,2}$, F. Risitano$^{2,4,6}$, F. Rizzo$^{1,4,5}$, P. Russotto$^5$, M. Trimarchi$^{2,6}$, C. Zagami$^{4,5}$
1. Dipartimento di Fisica e Astronomia “E. Majorana”, Universitá degli Studi di Catania, Catania, Italy
2. INFN-Sezione di Catania, Catania, Italy
3. DEIB Politecnico di Milano and INFN-Sezione di Milano, Milano, Italy
4. CSFNSM, Catania, Italy
5. INFN-LNS, Catania, Italy
6. Dipartimento MIFT, Università di Messina, Messina, Italy
$^*$rosaria.cavallaro@phd.unict.it
This contribution presents preliminary results from the study of the $^4$He+$^{12}$C reaction at 64 MeV, performed at INFN-LNS, aimed at investigating the $\gamma$-decay of excited states in $^{12}$C.
This study is particularly relevant because the determination of the decay widths of $^{12}$C excited states provides important insights into nucleosynthesis processes in astrophysical environments. In particular, the state at 7.65 MeV (known as Hoyle state, $J^\pi = 0^+$) plays a key role in the production of $^{12}$C during the helium-burning phase at $T\sim 10^8 K$, while the state at 9.64 MeV ($J^\pi = 3^-$) is involved in explosive astrophysical scenarios ($T > 2 \cdot 10^9 K$). The $\gamma$-decay width of the 9.64 MeV state has been estimated in some recent works [1,2] and further investigations on its properties are still ongoing. In this context, the analysis presented in this contribution is based on a measurement that represents an improvement over a previous experimental run, which results are discussed in [2]. The goal of this improvement is to increase the statistics. In this experiment CHIMERA multidetector [3] was employed to detect reaction products.
CHIMERA is capable of detecting both $\gamma$-rays and charged particles, and this feature enables the use of multifold coincidence analysis [2], allowing the detection of all final-state reaction products.
First results on Q-value spectra will be presented. In particular, the comparison between the spectra obtained using the kinematic definition of the Q-value and those derived from the missing-energy Q-value definition will be discussed. The missing-energy spectra can be reconstructed thanks to the possibility of performing a multifold coincidence analysis and this technique allows to overcome the problems due to the limited angular resolution of the detector and also to strongly reduce the background, which is a key point for this kind of measurements. Finally, first preliminary data analysis on $\gamma$-ray detection will be shown.
References
[1] M. Tsumura et al., Phys. Lett. B 817 (2021), 136283
[2] G. Cardella et al., Phys. Rev. C 104 (2021) 064315
[3] A. Pagano et al., Nucl. Phys. A 734, 504 (2004)