- Rocchini, M;
- Garrett, PE;
- Zielińska, M;
- Lenzi, SM;
- Dao, DD;
- Nowacki, F;
- Bildstein, V;
- MacLean, AD;
- Olaizola, B;
- Ahmed, ZT;
- Andreoiu, C;
- Babu, A;
- Ball, GC;
- Bhattacharjee, SS;
- Bidaman, H;
- Cheng, C;
- Coleman, R;
- Dillmann, I;
- Garnsworthy, AB;
- Gillespie, S;
- Griffin, CJ;
- Grinyer, GF;
- Hackman, G;
- Hanley, M;
- Illana, A;
- Jones, S;
- Laffoley, AT;
- Leach, KG;
- Lubna, RS;
- McAfee, J;
- Natzke, C;
- Pannu, S;
- Paxman, C;
- Porzio, C;
- Radich, AJ;
- Rajabali, MM;
- Sarazin, F;
- Schwarz, K;
- Shadrick, S;
- Sharma, S;
- Suh, J;
- Svensson, CE;
- Yates, D;
- Zidar, T
The excited states of N=44 ^{74}Zn were investigated via γ-ray spectroscopy following ^{74}Cu β decay. By exploiting γ-γ angular correlation analysis, the 2_{2}^{+}, 3_{1}^{+}, 0_{2}^{+}, and 2_{3}^{+} states in ^{74}Zn were firmly established. The γ-ray branching and E2/M1 mixing ratios for transitions deexciting the 2_{2}^{+}, 3_{1}^{+}, and 2_{3}^{+} states were measured, allowing for the extraction of relative B(E2) values. In particular, the 2_{3}^{+}→0_{2}^{+} and 2_{3}^{+}→4_{1}^{+} transitions were observed for the first time. The results show excellent agreement with new microscopic large-scale shell-model calculations, and are discussed in terms of underlying shapes, as well as the role of neutron excitations across the N=40 gap. Enhanced axial shape asymmetry (triaxiality) is suggested to characterize ^{74}Zn in its ground state. Furthermore, an excited K=0 band with a significantly larger softness in its shape is identified. A shore of the N=40 "island of inversion" appears to manifest above Z=26, previously thought as its northern limit in the chart of the nuclides.