Trapped Antihydrogen in Its Ground State

Antihydrogen atoms ((H) over bar) are confined in an Ioffe trap for 15-1000 s-long enough to ensure that they reach their ground state. Though reproducibility challenges remain in making large numbers of cold antiprotons ((p) over bar) and positrons (e(+)) interact, 5 +/- 1 simultaneously confined ground-state atoms are produced and observed on average, substantially more than previously reported. Increases in the number of simultaneously trapped (H) over bar are critical if laser cooling of trapped (H) over bar is to be demonstrated and spectroscopic studies at interesting levels of precision are to be carried out.