Reexamining carbon fusion

Carbon fusion has been a focus of considerable study in recent years with a number of innovative direct measurements and indirect studies of this astrophysically vital reaction. Carbon fusion has a strong impact on superbursts in x-ray binary systems, type Ia supernovae and nucleosynthesis in massive stars. A number of open questions about carbon fusion remain, including whether there are molecular resonances in 24Mg which enhance the fusion reaction or just a dearth of available states through which fusion can proceed, whether there is an hindrance process in the reaction and what is the branching into different light particles (protons, neutrons and ?? particles).

Indirect methods can provide insights into these questions. In this talk an ??-particle inelastic scattering experiment off 24Mg is reported using the K600 magnetic spectrometer at iThemba LABS in Cape Town, South Africa. Decay charged-particles were detected in the Coincidence Array for K600 Experiments (the CAKE), an array of double-sided silicon strip detectors placed at the target position of the spectrometer. A number of 0+ states were identified which may correspond to Hoyle-like near-threshold states which are able to significantly enhance the reaction cross section.