Low-energy isoscalar quadrupole strength in Ca-40 and Ca-48 from (p, p ' x) reactions

A decomposition of giant multipole strength in Ca-40 and C-48, is performed from angular correlations and emission angle integrated angular distributi ons of the reactions Ca-40(p,p' alpha (0))Ar-36, Ca-40(p,p'p(0))K-39 and Ca -48(p,p'n(0))Ca-47. The deduced B(E2) strength distributions agree reasonab ly well in shape and magnitude with the results of electron-induced experim ents. Previous suggestions of a systematic discrepancy of the total E2 stre ngths in the alpha (0) channel derived from hadronic and electromagnetic pr obes are shown to be unfounded. In Ca-48, for the first time evidence for s izable isoscalar E2 strength at low excitation energies, similar to Ca-40, could be established. (C) 2001 Elsevier Science B.V. All rights reserved.