Observation of Airy minimum in elastic and inelastic scattering of ${}^3$He from ${}^{12}$C at 50.5 and 60 MeV and alpha particle condensation in ${}^{12}$C

Abstract

Angular distributions for elastic and inelastic scattering of ${}^3$He from ${}^{12}$C were measured at energies 50.5 and 60 MeV. The Airy minimum of the prerainbow scattering was clearly observed in the angular distributions for the 0${}_2^{+}$ (7.65 MeV) state of ${}^{12}$C (Hoyle state). The experimental results were analyzed with a coupled channels method with double folding potentials derived from the microscopic wave functions for the ground 0${}_1^{+}$, 2${}^{+}$ (4.44 MeV), 3${}^{-}$ (9.64 MeV) and 0${}_2^{+}$ states. The analysis supports the view that the Hoyle state is a three alpha particle condensate with a large radius of dilute matter distribution.

Comments: 5 pages, 6 figures