First Laser-Controlled Antihydrogen Production

Lasers are used for the first time to control the production of antihydrogen ($\overline{\mathrm{H}}$). Sequential, resonant charge exchange collisions are involved in a method that is very different than the only other method used so far—producing slow $\overline{\mathrm{H}}$ during positron cooling of antiprotons in a nested Penning trap. Two attractive features are that the laser frequencies determine the $\overline{\mathrm{H}}$ binding energy, and that the production of extremely cold $\overline{\mathrm{H}}$ should be possible in principle—likely close to what is needed for confinement in a trap, as needed for precise laser spectroscopy.