Search for the chiral doublet bands in ¹²²Cs

High spin states in the odd-odd nucleus ¹²²Cs have been studied by in-beam γ-ray spectroscopy with a ¹⁰⁷Ag( ¹⁹F,1p3n) fusion-evaporation reaction at a beam energy of 85 MeV. A previously known πh _11/2 ⊗ νh _11/2 yrast band was confirmed and its spin I was re-examined. A ΔI = 2 band was identified, which together with another known ΔI = 2 band forms a side band of the πh _11/2 ⊗ νh _11/2 yrast band. The two observed πh _11/2 ⊗ νh _11/2 bands are proposed as a pair of chiral doublet bands in ¹²²Cs based on a systematic comparison with those in the neighbouring odd-odd Cs isotopes, as well as the relativistic mean field and the triaxial particle-rotor-model calculations.