Analogous negative parity spectra of¹²⁵Xe and¹²⁷Xe

The low spin states of the nucleus Xe-127 have been investigated with the (alpha, 2n) reaction by means of in-beam-gamma-spectroscopy, using the OSIRIS-cube-spectrometer at the FN TANDEM accelerator facility of the University of Cologne. In the negative parity system, four excited states for each of the spins 11/2(-)..15/2(-) and two 5/2(-)..9/2(-) - states could be established at excitation energies up to approximate to 1MeV above the Yrast line. With this new data, we are able to compare the non-Yrast states and their decay properties to the corresponding states of Xe-125, which had been studied with similar methods in Cologne. The almost one-to-one correspondence between the states of these neighboring neutron-odd nuclei is a clear indication that their excitations at low spin remain collective well above the Yrast line.