Antihelium-4 Mass (IMAGE) DOE/Brookhaven National Laboratory Caption This graph plots particle counts by mass, showing ordinary helium nuclei (He-3 and He-4) in orange, and their antimatter counterparts (antihelium-3 and antihelium-4) in blue. The plot illustrates that the newly discovered antimatter nuclei, antihelium-4, are very cleanly separated from the lighter isotopes, and are at the correct mass. Credit Brookhaven National Laboratory Usage Restrictions See guidelines at: http://www.bnl.gov/bnlweb/images_legal.html License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.