Resonances in 12C+12C fusion inside the carbon-burning Gamow window

Determine the total $\mathrm{12C}+\mathrm{12C}$ fusion $S*$-factor (alpha plus proton channels) for $E_{\mathrm{cm}}=1.5\ \text{to}\ 2.5\,\mathrm{MeV}$, the Gamow window for $T=5 \times 10^{8}\ \text{to}\ 10^{9}\,\mathrm{K}$, including the presence, energies and strengths of any resonances, and hence the reaction rate at $T=5 \times 10^{8}\ \text{to}\ 10^{9}\,\mathrm{K}$ to 20 percent. The answer must reconcile direct particle-gamma coincidence data, which extend down to about $E_{\mathrm{cm}} \sim 2.2\,\mathrm{MeV}$, with indirect Trojan-horse extractions that claim strong resonant enhancement below 2 MeV.

A direct measurement of the $\alpha$ and proton channels down to $E_{\mathrm{cm}} \sim 1.5\ \mathrm{MeV}$ with background low enough to resolve or exclude resonances, cross-checked against the Trojan-horse normalization.