Precision Measurement of the Hg203 Beta-Gamma Directional Correlation

A precise measurement of the $\ensuremath{\beta}\ensuremath{-}\ensuremath{\gamma}$ directional correlation of $^{203}\mathrm{Hg}$ as a function of the average $\ensuremath{\beta}$ energy $\overline{W}$ (in units $m{c}^{2}$) is reported. The values of the anisotropy coefficient ${A}_{22}(\overline{W})$ in the $\ensuremath{\beta}\ensuremath{-}\ensuremath{\gamma}$ directional correlation function $W(\ensuremath{\theta})=1+{A}_{22}(\overline{W}){P}_{2}(cos\ensuremath{\theta})$ are: ${A}_{22}(\overline{W}=1.15)=\ensuremath{-}0.007\ifmmode\pm\else\textpm\fi{}0.0009$, ${A}_{22}(\overline{W}=1.23)=\ensuremath{-}0.0016\ifmmode\pm\else\textpm\fi{}0.0006$, ${A}_{22}(\overline{W}=1.31)=\ensuremath{-}0.0020\ifmmode\pm\else\textpm\fi{}0.0010$, ${A}_{22}(\overline{W}=1.345)=\ensuremath{-}0.0018\ifmmode\pm\else\textpm\fi{}0.0005$, and ${A}_{22}(\overline{W}=1.38)=0.0018\ifmmode\pm\else\textpm\fi{}0.0011$.