The ALPHA Collaboration is a group of physicists from about 11 universities who work together (or "collaborate") to try to trap neutral antimatter. The neutral antimatter they are working to trap is antihydrogen. This is the antimatter version of hydrogen, the first atom in the periodic table. Antihydrogen, like hydrogen, has two oppositely charged particles. Hydrogen has a proton and an electron, and so antihydrogen would have an antiproton and a positron. A positron is the common name for the antielectron.