\begin{table}%t3 %\centering \par \caption{\label{tab:OMT}Band-averaged cross-polar leakage $\eta$ and effective rotation~$\delta$ measured for the flight model OMTs.} \begin{tabular}{lrrrrrr} \hline \hline \noalign{\smallskip} Feed & \multicolumn{2}{c}{Side arm} & \multicolumn{2}{c}{Main arm} & \multicolumn{2}{c}{Difference\tablefootmark{a}}\\ & $\eta_{\rm s}$ & $\delta_{\rm s}$ & $\eta_{\rm m}$ & $\delta_{\rm m}$ & $\bar{\eta}$ & $\bar{\delta}$ \\ LFI- & $10^{-3}$ & \degr & $10^{-3}$ & \degr & $10^{-3}$ & \degr \\ \hline 18 & 0.39 & $ 0.02$ & 0.29 & $ 0.97$ & 0.41 & $ 0.49$ \\ 19 & 0.46 & $ 0.44$ & 0.40 & $-$1.53 & 0.73 & $-$0.54 \\ 20 & 0.10 & $ 0.27$ & 0.18 & $-$0.89 & 0.25 & $-$0.26 \\ 22 & 0.26 & $ 0.54$ & 0.36 & $-$1.46 & 0.61 & $-$0.46 \\ 23 & 0.34 & $ 0.76$ & 0.34 & $-$1.41 & 0.70 & $-$0.33 \\ & & & & \\ 24 & 0.03 & $ 0.01$ & 0.02 & $-$0.37 & 0.04 & $-$0.18 \\ 25 & 0.18 & $-$0.02 & 0.07 & $-$0.75 & 0.16 & $-$0.39 \\ 26 & 0.42 & $ 0.95$ & 0.34 & $ 0.83$ & 0.38 & $ 0.89$ \\ & & & & \\ 27 & 0.02 & $-$0.02 & 0.02 & $ 0.40$ & 0.03 & $ 0.19$ \\ 28 & 0.04 & $ 0.16$ & 0.06 & $ 0.26$ & 0.05 & $ 0.21$ \\ \hline \end{tabular} \tablefoot{Values are weighted by the measured bandpass and the differential CMB spectrum. \tablefoottext{a}{effective $\bar{\eta}$ and $\bar{\delta}$ evaluated by integrating over the difference bandpasses, ${\cal M}_{QS} = {\cal W}_{\rm s}(\nu)/G_{\rm s} - {\cal W}_{\rm m}(\nu)/G_{\rm m}$.}}\vspace*{2.5mm} \end{table}