反氢和反原子

Antihydrogen and Antiatoms

自从狄拉克预言反粒子的存在后，虽然人们已经找到了几乎每个粒子的反粒子，但几代物理学家苦苦寻找着由反粒子组成的反原子．１９９６年１月ＣＥＲＮ宣布制成反氢原子，打开了通向反物质世界的大门，引起轰动．文章叙述这一重大发现的物理背景，报道了上述发现。

The existence of antimatter was suggested by Paul Dirac in 1931. About three generations have passed since the prediction and discovery of the positron and the antiproton, but up to 1995, atomic antimatter has neither been observed nor synthesized in the laboratory. An announcement by the CERN particle physics center in Geneva in January 1996 revealed that the researchers there have created a total of 11 antihydrogen atoms by using CERN's Low Energy Antiproton Ring (LEAR). Physicists are intensely excited at the prospect of being able to study this entirely new atom, because it will provide a fundamental test for physicists' understanding of nature. The next step of the antimatter project will be discussed and some speculations will be made in this paper.