$^{12}$C+$^{16}$O sub-barrier radiative capture cross-section measurements

TL;DR

This study measures the radiative capture cross-section of $^{12}$C and $^{16}$O at sub-barrier energies, revealing unexpected gamma decay pathways that suggest structural effects in $^{28}$Si.

Contribution

First measurement of $^{12}$C+$^{16}$O radiative capture cross-sections at sub-barrier energies showing new decay channels not explained by existing models.

Findings

Observation of strong feeding of intermediate states around 11 MeV.

Discrepancy with statistical decay models suggests structural effects.

Extraction of radiative capture cross-sections at low energies.

Abstract

We have performed a heavy ion radiative capture reaction between two light heavy ions, $^{12}$C and $^{16}$O, leading to $^{28}$Si. The present experiment has been performed below Coulomb barrier energies in order to reduce the phase space and to try to shed light on structural effects. Obtained $\gamma$-spectra display a previously unobserved strong feeding of intermediate states around 11 MeV at these energies. This new decay branch is not fully reproduced by statistical nor semi-statistical decay scenarii and may imply structural effects. Radiative capture cross-sections are extracted from the data.