Department of Physics, Graduate School of Science
I study triple alpha reaction. The triple alpha reaction is one of the most important reactions for nucleosynthesis in the universe. In triple alpha reaction, 3α particles change to 12C via 3α resonance states. Most 3α resonance states decay back to 3α particles, but rarely de-excite into 12C by γ-decay. Therefore, the γ-decay probability determines the 3α reaction rate.
3α reaction mainly via 0+ state (Hoyle state) and the γ-decay probability is already known. At high temperatures, however, the effect of higher excited states (e.g., 3-1 state, 2+2 state) is significant. Nevertheless, their γ-decay probabilities are still unmeasured due to their small value. Moreover, it is indicated that the uncertainty about the 3α rate due to the γ-decay probability of higher excited resonance states significantly impact the νp-process. Thus, I study measuring the γ-decay probability of 3-1 state in 12C using the original method: deuteron inelastic scattering in inverse kinematics.