Observing the ping-pong modality of the isospin degree of freedom in cluster emission from heavy-ion reactions

Thermodynamic and chemical two-body correlations of the isotope-resolved clusters are measured in 86Kr + 208Pb reactions at 25 MeV/u. The yield and kinetic variables of the A = 3 isobars are analyzed in coincidence with the intermediate mass fragments of 6 A 11. While the velocity spectra of both t and 3He exhibit scaling behavior over the type of the intermediate mass fragments, the yield ratios of t/ 3He correlate reversely to the neutron-to-proton ratio N/Z of the latter, showing the ping-pong modality of the N/Z of the emitted particles. The commonality that the N/Z of the residues keeps the initial system value is extended to the cluster emission in heavy ion reactions. The comparison to transport model calculations to the data is discussed.