Transverse asymmetry of γ rays from neutron-induced compound states of La 140

An $sp$-mixing model, which describes a compound nuclear reaction by mixing partial waves, predicts a correlation term in this reaction. A detailed study of the $sp$-mixing model is required to study the feasibility of a new type of time reversal symmetry violation search experiment. The correlation term ${\\mathbit{\\ensuremath{\\sigma}}}_{n}\\ifmmode\\cdot\\else\\textperiodcentered\\fi{}({\\mathbit{k}}_{n}\\ifmmode\\times\\else\\texttimes\\fi{}{\\mathbit{k}}_{\\ensuremath{\\gamma}})$ in the $^{139}\\mathrm{La}(\\stackrel{P\\vec}{n},\\ensuremath{\\gamma})$ reaction has been studied by measuring $\\ensuremath{\\gamma}$-ray and neutron energies utilizing epithermal polarized neutrons and germanium detectors. The transverse asymmetry for single $\\ensuremath{\\gamma}$-ray transition was measured to be $0.60\\ifmmode\\pm\\else\\textpm\\fi{}0.19$ in the $p$-wave resonance.