Inelastic form factors to alpha particle condensate states in 12C and 16O: what can we learn ?

Abstract

In order to discuss the spatial extention of the second 0+ state of 12C (Hoyle state), we analyze the inelastic form factor of electron scattering to the Hoyle state, which our 3 alpha condensate wave function reproduces very well like previous 3 alpha RGM/GCM models. The analysis is made by varying the size of the Hoyle state artificially. As a result, we find that only the maximum value of the form factor sensitively depends on its size, while the positions of maximum and minimum are almost unchanged. This size dependence is found to come from a characteristic feature of the transition density from the ground state to the Hoyle state. We further show the theoretical predictions of the inelastic form factor to the second 2+ state of 12C, which was recently observed above the Hoyle state, and of the inelastic form factor to the calculated third 0+ state of 16O, which was conjectured to correspond to the 4 alpha condensed state in previous theoretical work by the present authors.