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

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.

Comments: contribution to the 2nd Workshop on "State of the Art in Nuclear Cluster Physics" (SOTANCP2), Universite Libre de Bruxelles (Belgium), May 25-28, 2010, to be published in the International Journal of Modern Physics E