Triple {\alpha} Resonances in the Decay of Hot Nuclear Systems *

Abstract

The Efimov (Thomas) trimers in excited 12 C nuclei, for which no observation exists yet, are discussed by means of analyzing the experimental data of 70(64) Zn( 64 Ni) + 70(64) Zn( 64 Ni) reactions at beam energy of E/A=35MeV/nucleon. In heavy ion collisions, the {\alpha}s interact with each other and can form complex systems such as 8 Be and 12 C. For the 3{\alpha} systems, multi resonance processes give rise to excited levels of 12 C. The interaction between any two of the 3{\alpha} particles provides events with one, two or three 8 Be. Their interfering levels are clearly seen in the minimum relative energy distributions. Events of three couple {\alpha} relative energies consistent with the ground state of 8 Be are observed with the decrease of the instrumental error at the reconstructed 7.458 MeV excitation energy of 12C, which was suggested as the Efimov (Thomas) state.