Evidence for octupole correlation in Z=50 Sn isotopes: Spectroscopy of Sn112

High-spin states in ¹¹²Sn were investigated using the ¹⁰³Rh(¹²C, 1p2n) reaction at a beam energy of 62 MeV. Six electric dipole $E1$ transitions linking positive- and negative-parity intruder bands have been identified in ₅₀¹¹²Sn through γ-ray spectroscopy. The experimental reduced $E1$ transition probabilities $B(E1)$, derived from level lifetimes by means of the Doppler-shift attenuation method, are of the order of 10^-4 W.u., which gives evidence for the octupole correlation in ¹¹²Sn. The systematics of the reduced $E1$ transition probabilities and neutron energy levels of 5/2⁺ and 11/2^- in Xe isotopes suggest an enhanced octupole correlation at neutron number $N=62$, which is supported by the relativistic Hartree-Bogoliubov calculations.