Prerainbow Oscillations in ${}^3$He Scattering from the Hoyle State of ${}^{12}$c and Alpha Particle Condensation

Abstract

${}^3$He+${}^{12}$C scattering is studied in a coupled channel method by using a double folding model with microscopic wave functions of ${}^{12}$C. Experimental angular distributions in elastic and inelastic scattering to the $2^{+}$ (4.44 MeV), 0${}_2^{+}$ (7.65 MeV) and 3${}^{-}$ (9.63 MeV) states of ${}^{12}$C are well reproduced. It is found that the Airy minimum of the prerainbow oscillations for the Hoyle state is considerably shifted to a larger angle due to its dilute density distribution compared with that of the normal ground state in agreement with the idea of $\alpha$ particle condensation.

6 pages, 3 figures