Signature Of A 2-Phonon State Through Its Proton Decay Pattern

Inelastic scattering of 50 MeV/nucleon Ca-40 on Ca-40 was measured in coincidence with protons in order to investigate the excitation and decay of highly excited states in Ca-40. The proton decay pattern corresponding to an excitation region around 34 MeV shows the characteristic behavior expected of the direct decay of a two-phonon state. Thus, by using this novel method, the presence of a double-phonon state built with isoscalar giant resonances in Ca-40 is demonstrated.