Formation of cold Cs2 molecules through photoassociation

We report on the formation of translationally cold Cs-2 ground-state molecules through photoassociation of laser-cooled cesium atoms in a magneto-optical trap. The cold molecules are obtained after spontaneous decay of photoassociated molecules, and detected after pulsed-laser photoionization into Cs-2(+) ions. Photoassociation spectra of cesium attractive molecular states below the 6S(1/2) + 6P(3/2) dissociation limits are reported, obtained with both ion detection and trap-loss method. A temperature as low as 20(-5)(+15) has been measured for the molecular cloud.