Speaker
Description
3He induced reactions allow to investigate the spectroscopy of high excitation energy regions of light compound nuclei that can be formed in low energy reactions [Lom21]. We recently performed a new experiment of this type, HELICA, with the solid-state hodoscope OSCAR [Del18] at the AN-2000 accelerator of the Laboratori Nazionali di Legnaro (INFN-LNL). In the experiment, a 3He beam, with energies ranging from about 1400 keV to 2200 keV was delivered to a thin 13C target. Thanks to the excellent identification capabilities of the HELICA setup, several nuclear reactions, including 13C(3He,p)15N, 13C(3He,d)14N, 13C(3He,alpha)12C, leading the residual nucleus to several excited states, were correctly identified. The latter, in particular, is an excellent probe for the detailed spectroscopy of the 16O compound nucleus. In the talk, we show preliminary angular distributions and excitation functions of the cross section for the 13C(3He,a0), 13C(3He,a1), 13C(3He,a2) reactions in a broad angular domain, and discuss the impact on the spectroscopy of 16O. The preliminary values of the branching ratios between the transitions populating the ground state and the Hoyle state show an energy dependence that suggest the occurrence of a strongly clustered state in 16O at about 24 MeV excitation energy.
References
[Del18] D. Dell’Aquila et al., Nucl. Instr. Meth. Phys. Res. A 877 (2018) 227
[Lom21] I. Lombardo et al., J. Phys. G: Nucl. Part. Phys. 48 (2021) 065101
