Search for possible alpha-condensate states in $^{20}$Ne

Abstract

The root mean square radii of 20 Ne in the short-lived excited states were experimentally deduced for the first time from the analyses of 𝛼+ 20 Ne diffraction scattering. Differential cross sections of the elastic and inelastic 𝛼+ 20 Ne scattering in the incident energy range from a few MeV/nucleon up to 100 MeV/nucleon were analyzed by the modified diffraction model. No significant radius enhancement for the members of K 𝜋 = 0 + 1 and K 𝜋 = 2 − bands in comparison with the ground state was observed. At the same time 20% radius enhancement was obtained for the K 𝜋 = 0 − 1 band members. Moreover, for the 0 + 2 state located above 𝛼emission threshold increased radius was observed. This result can speak in favor of possible 𝛼-condensate structure of the 0 + 2 state and can be considered as a possible analog of the famous 7.65-MeV 0 + 2 Hoyle state of 12 C.