Monday, April 25, 2011

It's official: Heaviest antimatter found

STAR Collaboration / RHIC / BNL
This image shows a three-dimensional rendering of the STAR time projection chamber surrounded by the time-of-flight barrel (the outermost cylinder). Particle tracks spray out from the collision, including a meter-long track from an antihelium-4 nucleus (highlighted in bold red).

The reports began circulating a few weeks ago, and today's publication in the journal Nature makes it official: Physicists have detected the heaviest bits of antimatter ever found on Earth. And that record is likely to stand for a long, long time.
Members of the STAR collaboration at the Relativistic Heavy Ion Collider, based at Brookhaven National Laboratory in New York, say they've seen the traces of 18 nuclei of antihelium-4 among about half a trillion particles produced by almost a billion gold-ion collisions at RHIC. These nuclei are like regular helium nuclei, except that instead of having two protons and two neutrons, they have two negatively charged antiprotons and two antiprotons. Article with interesting links posted here

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