Giant resonances in the doubly magic nucleus 48Ca from the (e, e'n) reaction.
The 48Ca(e,e(')n) reaction has been investigated for excitation energies 11-25 MeV and momentum transfers 0.22-0.43 fm(-1) at the superconducting Darmstadt electron linear accelerator S-DALINAC. Electric dipole and quadrupole plus monopole strength distributions are extracted from a multipole decomposition of the spectra. Their fragmented structure is described by microscopic calculations allowing for coupling of the basic particle-hole excitations to more complex configurations. Comparison of the excitation spectrum of the residual nucleus 47Ca with statistical model calculations reveals a 39(5)% contribution of direct decay to the damping of the giant dipole resonance.
Strauch
S
S
Institut fur Kernphysik, Technische Universitat Darmstadt, D-64289 Darmstadt, Germany.
von Neumann-Cosel P
Rangacharyulu
C
C
Richter
A
A
Schrieder
G
G
Schweda
K
K
Wambach
J
J