The proton spectra of the giant quadrupole resonance decay in ${}^{40}$Ca is analyzed. The decay mechanism of this excitation is studied by the inclusion of the semidirect, preequilibrium, and statistical modes through the chaining evolution of the particle-hole configurations. Strong evidence for the contribution of preequilibrium decay of the giant resonance is established.

• Received 12 November 1996

DOI:https://doi.org/10.1103/PhysRevC.55.1246