Investigation of IVGRs via theNi(t,He)Co reaction

Abstract

A 130 MeV primary tritium beam, newly developed at the superconducting cyclotron AGOR, has been used for the investigation of 1ħω and 2ħω isovector giant resonances in58Co via theτ+ channel. The angular distributions of double-differential cross sections have been extracted betweenEx = 7 and 30 MeV fromθlab = 0° to 6°. A DWBA analysis with normal-mode (NM) wave functions and a multipole-decomposition analysis (MDA) indicate strength for the monopole resonances (dominated by the spin-flip transition) fragmented between 10 and 27 MeV excitation energy, in rather good agreement with preliminary RPA calculations.