Enrique Martinez Quiroz

Carbon and oxygen burning reactions, in particular, ${}^{12}\mathrm{C}+{}^{12}\mathrm{C}$ fusion, are important for the understanding and interpretation of the late phases of stellar evolution as well as the ignition and nucleosynthesis in cataclysmic binary systems such as type Ia supernovae and x-ray superbursts. A new measurement of this reaction has been performed at the University of Notre Dame using particle-$\gamma$ coincidence techniques with SAND (a silicon detector array) at the high-intensity 5U Pelletron accelerator. New results for ${}^{12}\mathrm{C}+{}^{12}\mathrm{C}$ fusion at low energies relevant to nuclear astrophysics are reported. They show strong disagreement with a recent measurement using the indirect Trojan Horse method. The impact on the carbon burning process under astrophysical scenarios will be discussed.

The elastic scattering of the radioactive proton-rich carbon isotope ${}^{10}\mathrm{C}$ has been investigated. A full differential angular distribution for the elastic scattering of ${}^{10}\mathrm{C}$ on a ${}^{58}\mathrm{Ni}$ target has been measured at $E_{\mathrm{Lab}}=35.3$ MeV, which is just above the Coulomb barrier for this system ($V_B=27$ MeV). The obtained angular distribution was analyzed in terms of coupled-channels, coupled-reaction-channels, and continuum-discretized coupled-channels calculations. In the coupled-channels calculation, several inelastic transitions of the target and the first ($2^{+}$) excited state of the ${}^{10}\mathrm{C}$ projectile were considered. The coupling to the first ($2^{+}$) excited state of ${}^{10}\mathrm{C}$ was shown to be very important to describe the rising of the cross section at backward angles. We also performed an analysis with the continuum-discretized coupled channels, considering the ${}^9\mathrm{B}+p$ and ${}^6\mathrm{Be}+\alpha$ channels, which indicated a strong cluster configuration for the ${}^{10}\mathrm{C}$ projectile.