Determination of the B(E3, 0(+) -> 3(-))-excitation strength in octupole-correlated nuclei near A approximate to 224 by the means of Coulomb excitation at REX-ISOLDE

The IS475 collaboration conducted Coulomb-excitation experiments with post-accelerated radioactive Rn-220 and Ra-224 beams at the REX-ISOLDE facility. The beam particles (E-beam approximate to 2.83 MeV/u) were Coulomb excited using Ni-60, Cd-114, and Sn-120 scattering targets. De-excitation gamma-rays were detected employing the Miniball array and scattered particles were detected in a silicon detector. Exploiting the Coulomb-excitation code GOSIA for each nucleus several matrix elements could be obtained from the measured gamma-ray yields. The extracted < 3-vertical bar vertical bar(E) over cap3 vertical bar vertical bar 0(+>) matrix element allows for the conclusion that, while Rn-220 represents an octupole vibrational system, 224Ra has already substantial octupole correlations in its ground state. An observation that has implications for the search of CP-violating Schiff moments in the atomic systems of the adjacent odd-mass nuclei.