Quasi-gamma bands in even-mass Xe AND Ba nuclei

Low-lying excited states of ^124,126Xe and ¹³²Ba have been studied by means of in-beam γ-ray spectroscopy in (p, xny) reactions. Excitation functions, angular distributions and γ-γ coincidence spectra were obtained. The 2₂⁺ , 3⁺, 4₂⁺ and 5⁺ levels were observed at the following excitation energies in keV: 846.4(2₂⁺), 1247.5(3⁺), 1437.3 (4₂⁺), 1836.6(5⁺) in ¹²⁴Xe, 879.7(2₂⁺), 1317.3(3 ⁺), 1488.2(4₂⁺), 1903.1(5 ⁺) in ¹²⁶Xe and 1032.1(2₂⁺), 1511.3(3⁺), 1729.9(4₂⁺) in ¹³²Ba. The 2214.3 and 2561.7 keV levels in ¹²⁶Xe were tentatively assigned as the 6₂⁺ and 7⁺ levels, respectively. These 2₂⁺, 3 ⁺, 4₂⁺, 5⁺, 6₂⁺and 7⁺ levels are interpreted as members of a quasi-γ band. The E2/M1 mixing ratios of the 2₂⁺ → 2₁⁺ transitions in ^124,126Xe and ¹³²Ba were obtained as + 6.3^+5.3_?2.0 + 10.8^7.8_?3.2 and + 8.3^+4.9_?2.2, respectively.