Spin dependence in the \(p\)-wave resonance of \({^{139}\vec{\rm{La}}+\vec{n}}\)

We measured the spin dependence in a neutron-induced \(p\)-wave resonance by using a polarized epithermal neutron beam and a polarized nuclear target. Our study focuses on the 0.75~eV \(p\)-wave resonance state of \(^{139}\)La+\(n\), where largely enhanced parity violation has been observed. We determined the partial neutron width of the \(p\)-wave resonance by measuring the spin dependence of the neutron absorption cross section between polarized \(^{139}\rm{La}\) and polarized neutrons. Our findings serve as a foundation for the quantitative study of the enhancement effect of the discrete symmetry violations caused by mixing between partial amplitudes in the compound nuclei.