Experimental investigation of alpha-gas states using high-multiplicity particle spectroscopy

The onset of a new state of matter in the nucleus, whereby the system can be described as a dilute gas of alpha-particles, represents a fantastic probe of the nuclear force. The observables from such an alpha-gas state are discussed here in tandem with a discussion of traditional alpha-cluster structure. An experiment, utilising a high energy compound nucleus reaction to study the \(^1\)\(^2\)C(\(^1\)\(^6\)0,7-alpha) reaction was performed at LNS Catania to search for the signatures of such a state of matter. Direct evidence of near-threshold alpha-gas states was found to be impeded by the effect of the Coulomb barrier. The break-up of the system into alpha-particles was seen to exceed the predictions from a statistical decay model of the compound nucleus which was performed. These results were instead compared with the Fermi break-up model which showed a greater agreement with the data but the limitations of the model meant an exact agreement was not achieved. No evidence of alpha-condensation was found in this experiment however an improved experiment where the effect of the Coulomb barrier is no longer important is presented as a future probe of this structure