Members of the international STAR collaboration at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory have observed antihelium-4. This is the heaviest antinucleus detected so far, following the discovery of the first antihypernucleus (an antiproton, an antineutron and a A) by the same collaboration just a year ago. After sifting through 0.5 x 1012 tracks in data for 109 gold-gold collisions at centre-of-mass energies of 200 GeV and 62 GeV per nucleon-nucleon pair, the STAR collaboration found 18 events with the signature of the antihelium-4 nucleus, which is distinguished by its mass together with its charge of-2.
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机译：Brookhaven国家实验室的相对论重离子对撞机（RHIC）上的国际STAR合作成员观察到antihelium-4。一年前，通过相同的合作发现了第一个抗超核（抗质子，抗中子和A），这是迄今为止检测到的最重的抗核。在以200 GeV和62 GeV每个核子对的重心能量对109次金-金碰撞进行数据筛选后，在STAR的数据中筛选了0.5 x 1012条轨迹后，STAR合作发现了18个事件，它们带有抗氦4核的签名，它的特点是其质量加上2的电荷。
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