Direct observation of ultracold molecular reactions*

Ultracold atoms and molecules provide a new platform to explore chemical reactions at ultralow temperatures. In this regime, reactions could proceed surprisingly efficiently due to their quantum mechanical nature. We are investigating a likely~4-center reaction, 2KRb-\textgreater K2$+$Rb2$+$KE (1.24 meV), in the temperature regime below 1 micro-Kelvin. Towards this goal, we have built an apparatus that combines AMO techniques for ultracold reagent preparation and physical chemistry techniques for reaction product detection through velocity-map imaging (VMI) of ions. I will report our first results on direct observation of ultracold molecular reactions.