Lifetime study of particle-hole excitations in the semimagic nucleus94Ru

Character of particle-hole excitations in94Ru deduced fromγ-ray angular correlation and linear polarization measurements

“…In other words, the 1p 1/2 proton state acts only as a spectator in these excitations, as already pointed out in Ref. [30]. Therefore, the structure of these states should be quite similar to the corresponding positive-parity states emerging from excitations of five proton holes in the shell 0g 9/2 .…”

“…A previous lifetime study of high-spin states in 94 Ru measured the 11 − (4489 keV) and 5 − (2624 keV) levels to have lifetimes of 1097 and 731 ps, respectively [30]. As can be seen in Fig.…”

“…Based on the observed γ -γ coincidences and angular distribution measurements the level scheme of the semimagic (N = 50) 94 Ru nucleus was previously interpreted as two main even-and odd-parity groups of states built primarily on proton single-particle structures from the 0g 9/2 and 1p 1/2 subshells [17,30,31]. The spin-parity assignments for some of the strongest populated states deduced in this work from linear polarization and angular correlation measurements confirm, unambiguously, this picture.…”

“…The agreement between calculated and experimental level energies for these states is typically quite good while, for states above 6 MeV excitation energy, the precision of the theoretical predictions is significantly reduced. Several calculations using different shell-model configuration spaces have been performed [17,18,30,32,33] in order to interpret the structure of high-lying states above I 13. The calculation presented in Ref.…”

“…[30] were used together with the measured relative intensities to extract partial decay rates and reduced transition probabilities of E1 transitions between the positive-and the negative-parity states. The results are shown in Table II.…”