First Measurement of the g Factor in the Chiral Band: The Case of the ^{128}Cs Isomeric State

• Published in: Physical review letters Vol. 120; no. 2; p. 022502
• Main Authors: Grodner, E, Srebrny, J, Droste, Ch, Próchniak, L, Rohoziński, S G, Kowalczyk, M, Ionescu-Bujor, M, Ur, C A, Starosta, K, Ahn, T, Kisieliński, M, Marchlewski, T, Aydin, S, Recchia, F, Georgiev, G, Lozeva, R, Fiori, E, Zielińska, M, Chen, Q B, Zhang, S Q, Yu, L F, Zhao, P W, Meng, J
• Format: Journal Article
• Language: English
• Published: United States 12.01.2018
• ISSN: 1079-7114
• DOI: 10.1103/PhysRevLett.120.022502

The g factor of the 56 ns half-life isomeric state in ^{128}Cs has been measured using the time-differential perturbed angular distribution method. This state is the bandhead of the positive-parity chiral rotational band, which emerges when an unpaired proton, an unpaired neutron hole, and an even-even core are coupled such that their angular momentum vectors are aplanar (chiral configuration). g-factor measurements can give important information on the relative orientation of the three angular momentum vectors. The measured g factor g=+0.59(1) shows that there is an important contribution of the core rotation in the total angular momentum of the isomeric state. Moreover, a quantitative theoretical analysis supports the conclusion that the three angular momentum vectors lie almost in one plane, which suggests that the chiral configuration in ^{128}Cs demonstrated in previous works by characteristic patterns of electromagnetic transitions appears only above some value of the total nuclear spin.