Transverse asymmetry of individual γ-rays in the ¹³⁹La(n⃗, γ)¹⁴⁰La reaction

The enhancement of the parity-violating asymmetry in the vicinity of p-wave compound nuclear resonances was observed for a variety of medium-heavy nuclei. The enhanced parity-violating asymmetry can be understood using the s-p mixing model. The s-p mixing model predicts several neutron energy-dependent angular correlations between the neutron momentum kₙ, neutron spin σₙ, γ-ray momentum k_γ, and γ-ray polarization σ_γ in the (n,γ) reaction. In this paper, the improved value of the transverse asymmetry of γ-ray emissions, corresponding to a correlation term σ⃗ₙ·( kₙ× k_γ) in the ¹³⁹La( n,γ)¹⁴⁰La reaction, and the transverse asymmetries in the transitions to several low excited states of ¹⁴⁰La are reported.