Nonlocalized motion in a two-dimensional container of α particles in 3- and 4- states of 12C

The first 3^- and 4^- states of ¹²C are studied in the present container model, in which the shift parameter is introduced to break the parity symmetry for projecting out the negative-parity states. Taking the limit as the shift parameter approaches zero and by variational calculations for one-deformed size parameter, the local energy minima are obtained for the 3^- and 4^- states. It is found that the obtained single Tohsaki-Horiuchi-Schuck-Röpke (THSR) wave functions for 3^- and 4^- states are 96% and 92% equivalent to the corresponding generator coordinate method (GCM) wave functions, respectively. The calculated intrinsic densities further show that these negative-parity states of three clusters, different from the traditional understanding of a rigid triangle structure, are found to have nonlocalized clustering structure in the two-dimensional container picture.