Evolution of single-particle structure near the N=20 island of inversion

The single-particle properties of Mg29 have been investigated via a measurement of the Mg28(d,p)Mg29 reaction, in inverse kinematics, using the ISOLDE Solenoidal Spectrometer. The negative-parity intruder states from the fp shell have been identified and used to benchmark modern shell-model calculations. The systematic data on the single-particle centroids along the N=17 isotones show good agreement with shell-model predictions in describing the observed trends from stability toward O25. However, there is also evidence that the effect of the finite geometry of the nuclear potential is playing a role on the behavior of the p orbitals near the particle-emission threshold.