Direct Measurement of the $^{11}$C$(\alpha,p)^{14}$N Reaction

A recent simulation of the rp-process in neutrino-driven winds in type II supernovae ($\nu p$-process) suggests that the $^{11}$C$(\alpha,p)^{14}$N reaction could be an important breakout pass from the pp-chain region to the CNO region. However, there are only very limited experimental information of the reaction cross section available from the time-reverse reaction studies. In order to determine the reaction rate of $^{11}$C$(\alpha,p)^{14}$N, a direct measurement by means of the thick-target inverse-kinematics method has recently been performed using low-energy $^{11}$C beams from the CNS Radioactive Ion Beam (CRIB) separator, a $^4$He gas target and $\Delta$E-E position-sensitive silicon telescopes at three downstream angles. The experiment covered $E_{\rm CM}$ = 0.5-5 MeV corresponding to the stellar temperature of 1.5-7GK. The obtained reaction cross section including some resonances and transitions to the excited states of $^{14}$N will be reported.