Disappearance of fusionlike residues and the nuclear equation of state

Abstract

The cross sections for massive residues from ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ ${+}^{40}$Ca and ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ar}$ ${+}^{27}$Al collisions were calculated with an improved Boltzmann-Uehling-Uhlenbeck equation. The calculated residue cross sections decrease with incident energy, an effect which does not appear related to the residue excitation energy. Larger residue cross sections result from calculations with larger in-medium nucleon-nucleon cross sections or with equations of state which are less attractive at subnuclear density. This dual sensitivity may be eliminated by measurements of observables associated with the coincident light particles.