Search for parity violation in 93Nb neutron resonances

A new search has been performed for parity violation in the compound nuclear states of ${}^{94}\mathrm{Nb}$ by measuring the helicity dependence of the neutron total cross section. Transmission measurements on a thick niobium target were performed by the time-of-flight method at the Manuel Lujan Neutron Scattering Center with a longitudinally polarized neutron beam in the energy range 32 to 1000 eV. A total of 18 p-wave resonances in ${}^{93}\mathrm{Nb}$ were studied with none exhibiting a statistically significant parity-violating longitudinal asymmetry. An upper limit of $1.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}7}$ eV (95% confidence level) was obtained for the weak spreading width ${\ensuremath{\Gamma}}_{w}$ in ${}^{93}\mathrm{Nb}.$