We have analyzed ${}^3\mathrm{He}$ scattering from ${}^{12}\mathrm{C}$ at 34.7 and 72 MeV in a coupled channel method with a double folding potential derived from the precise wave functions for the ground $0^{+}$ state and $0_2^{+}$ (7.65 MeV) Hoyle state, which has been suggested to be an $\alpha$ particle condensate. It is found that strong refraction of ${}^3\mathrm{He}$ in the Hoyle state can be clearly seen in the experimental angular distribution at a low incident energy region as an Airy minimum of the prerainbow oscillations.

• Received 22 December 2006

DOI:https://doi.org/10.1103/PhysRevC.75.044609