Proton versus neutron excitations in the high-spin spectrum of102Cd

Using the reaction ${}^{58}\mathrm{Ni}{(}^{50}\mathrm{Cr},\ensuremath{\alpha}$ $2p)$ and the coincidence recoil distance Doppler shift technique, we determined picosecond lifetimes of high-spin states in ${}^{102}\mathrm{Cd}.$ The positive-parity yrast and yrare cascades evidence the competition and interplay of the two proton holes in the ${g}_{9/2}$ orbit and four neutrons in the ${d}_{5/2},$ ${g}_{7/2},$ and ${h}_{11/2}$ orbits, outside the $Z=N=50$ ${}^{100}\mathrm{Sn}$ core. At positive parity, this interplay leads to multiplets of states in the spin range ${6}^{+}--{10}^{+},$ some of which are connected by very weak $E2$ transitions. At higher spins, spin-aligned proton holes and neutrons lead to magnetic rotation. Energies and transition strengths when compared with the predictions of several shell model calculations reveal the high sensitivity on the model parameters.