Constraining the ¹²C+¹²C fusion cross section for astrophysics

¹ Nuclear Science Lab, University of Notre Dame, Notre Dame, Indiana USA 46556
² Lawrence Livermore National Laboratory, Livermore, California USA 94551
³ Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China
⁴ Department of Physics, University of Basel, Basel, Switzerland

^a e-mail: bucher3@llnl.gov

Published online: 28 May 2015

Abstract

The ¹²C+¹²C reaction is one of the single most important nuclear reactions in astrophysics. It strongly influences late evolution of massive stars as well as the dynamics of type Ia supernovae and x-ray superbursts. An accurate estimation of the cross section at relevant astrophysical energies is extremely important for modeling these systems. However, the situation is complicated by the unpredictable resonance structure observed at higher energies. Two recent studies at Notre Dame have produced results which help reduce the uncertainty associated with this reaction. The first uses correlations with the isotope fusion systems, ¹²C+¹³C and ¹³C+¹³C, to establish an upper limit on the resonance strengths in ¹²C+¹²C. The other focuses on the specific channel ¹²C+¹²C→²³Mg+n and its low-energy measurement and extrapolation which is relevant to s-process nucleosynthesis. The results from each provide important constraints for astrophysical models.