<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>Λ</mml:mi></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mover accent="true"><mml:mi>Λ</mml:mi><mml:mo>¯</mml:mo></mml:mover></mml:math>Production in Central Pb-Pb Collisions at 40, 80, and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mn>158</mml:mn><mml:mi>A</mml:mi><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi mathvariant="normal">G</mml:mi><mml:mi mathvariant="normal">e</mml:mi><mml:mi mathvariant="normal">V</mml:mi></mml:math>

Production of Lambda and Antilambda hyperons was measured in central Pb-Pb collisions at 40, 80, and $158A\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$ beam energy on a fixed target. Transverse mass spectra and rapidity distributions are given for all three energies. The $\ensuremath{\Lambda}/\ensuremath{\pi}$ ratio at midrapidity and in full phase space shows a pronounced maximum between the highest BNL Alternating Gradient Synchrotron and $40A\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$ CERN Super Proton Synchrotron energies, whereas the $\overline{\ensuremath{\Lambda}}/\ensuremath{\pi}$ ratio exhibits a monotonic increase.