Measurement of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mi>π</mml:mi><mml:mrow><mml:mo>−</mml:mo></mml:mrow></mml:msup><mml:mi>p</mml:mi><mml:mo>→</mml:mo><mml:mi>η</mml:mi><mml:mi>n</mml:mi></mml:mrow></mml:math>from threshold to<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mi>p</mml:mi><mml:mrow><mml:msup><mml:mi>π</mml:mi><mml:mrow><mml:mo>−</mml:mo></mml:mrow></mml:msup></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn>747</mml:mn><mml:mspace width="0.3em"/><mml:mtext>MeV</mml:mtext><mml:mo>/</mml:mo><mml:mi>c</mml:mi></mml:mrow></mml:math>

The differential cross section for \ensuremath{\eta} production in reaction ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}\ensuremath{\eta}n$ has been measured over the full angular range at seven incident ${\ensuremath{\pi}}^{\ensuremath{-}}$ beam momenta from threshold to ${p}_{{\ensuremath{\pi}}^{\ensuremath{-}}}=747$ MeV/c using the Crystal Ball multiphoton spectrometer. The angular distributions are S wave dominated. At 10 MeV/c above threshold, a small D-wave contribution appears that interferes with the main S wave. The total \ensuremath{\eta} production cross section ${\ensuremath{\sigma}}^{\mathrm{tot}}$ is obtained by integration of $d\ensuremath{\sigma}/d\ensuremath{\Omega}$. Starting at threshold, ${\ensuremath{\sigma}}^{\mathrm{tot}}$ rises rapidly, as expected for S-wave-dominated production. The features of the ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}\ensuremath{\eta}n$ cross section are strikingly similar to those of the SU(3) flavor-related process ${K}^{\ensuremath{-}}p\ensuremath{\rightarrow}\ensuremath{\eta}\ensuremath{\Lambda}$. Comparison of the ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}\ensuremath{\eta}n$ reaction is made with \ensuremath{\eta} photoproduction.