Doorway state approximation and sign correlations in parity nonconservation in compound neutron resonances

摘要: The nonzero average parity-nonconserving longitudinal analyzing powers for p-wave neutron resonances in compound nuclear systems are analyzed within the giant J=${0}^{\mathrm{\ensuremath{-}}}$ resonance doorway model. Assuming that parity-nonconservation interaction can be approximated by a one-body operator of type \ensuremath{\sigma}\ensuremath{\cdot}p, we find observed fixed sign asymmetry arises naturally does not enhance size constant asymmetry. model prediction symmetry is shown to similar obtained single-particle In particular, if one retains only first-order contribution power, very large matrix element 〈4${\mathit{p}}_{1/2}$\ensuremath{\Vert}${\mathit{V}}_{\mathrm{pv}}$\ensuremath{\Vert}5${\mathit{s}}_{1/2}$〉\ensuremath{\simeq}75\ifmmode\pm\else\textpm\fi{}50 eV needed reproduce This value contradiction with 2 estimated from experimentally measured spreading width parity-violating using