First observation of the π0h11/2⊗ν0h9/2 partner orbital configuration in the odd-odd

B. Moon¹,

A. Gargano²,

H. Naïdja³

et al.

Abstract

The β-decay scheme of 138 Te and the level structure of 138 I is reported for the first time. The experiment was performed at the Radioactive Isotope Beam Factory of RIKEN, as one of the EUROBALL-RIKEN Cluster Array campaigns. Secondary radioactive ions, including 138 Te and 138 Sb, were produced by the in-flight fission of a 238 U beam with the energy of 345 MeV per nucleon. From the β decay of 138 Te, the level scheme of 138 I was supplemented with new spin and parity assignments, such as the low-lying negative-parity states and a positive-parity 1 + state. This 1 + state can be interpreted as being associated with the π 0h 11/2 ⊗ ν0h 9/2 partner orbital configuration populated by the Gamow-Teller transition between a neutron in the 0h 9/2 orbital and a proton in the 0h 11/2 orbital. Details of the structure of 138 I are discussed in terms of the proton-neutron interactions and Gamow-Teller transition strength within the theoretical context of shell-model calculations.