Production of $\alpha$-particle condensate states in heavy-ion collisions

TL;DR

This study investigates the production of alpha-particle condensate states in heavy-ion collisions by analyzing specific excited states of carbon-12 and oxygen-16, using experimental criteria to identify potential condensate states.

Contribution

The paper presents experimental evidence and analysis methods for identifying alpha-particle condensate states in nuclear reactions, focusing on specific excited states of light nuclei.

Findings

Identification of candidate alpha-condensate states in $^{12}$C and $^{16}$O

Isolation of direct 3-alpha decay events from the Hoyle state

Experimental criteria based on emission simultaneity and energy equality

Abstract

The fragmentation of quasi-projectiles from the nuclear reaction $^{40}Ca$ + $^{12}C$ at 25 MeV/nucleon was used to produce excited states candidates to $\alpha$-particle condensation. The experiment was performed at LNS-Catania using the CHIMERA multidetector. Accepting the emission simultaneity and equality among the $\alpha$-particle kinetic energies as experimental criteria for deciding in favor of the condensate nature of an excited state, we analyze the $0_2^+$ and $2_2^+$ states of $^{12}$C and the $0_6^+$ state of $^{16}$O. A sub-class of events corresponding to the direct 3-$\alpha$ decay of the Hoyle state is isolated.