Forschungszentrum Jülich - Annual Report 2012

Annual Report 2012 | Forschungszentrum Jülich Sharingknowledge 65 E ach elementary particle in nature has a ‘mirror image’. This anti- particle has the same mass, but an opposite electric charge. What we call matter consists of particles, and antimatter consists of the associated antiparticles. According to our present knowledge, the universe was created in the Big Bang, which produced as much matter as antimatter. However, we owe our existence to the imbalance between matter and antimatter. Without this asymmetry, matter and antimatter would have completely annihilated each other after the Big Bang and there would be no galaxies, planets, or humans. This prompts two questions: Are there regions in our universe that consist entirely of antimatter? And if there aren’t any, how did the matter- antimatter asymmetry come to exist? Researchers from Aachen and Jülich are working together to answer these questions and therefore established JARA-FAME on 1 August 2012 (p. 46). The first question will hopefully be answered by the Alpha Magnetic Spec- trometer (AMS) on the International Space Station, where the device is in- vestigating cosmic rays with previously unachievable precision. If it could detect only one single anticarbon nucleus, this would be positive proof that stars con- sisting of antimatter do exist. The first results presented by the AMS collabora- tion, which is headed by Physics Nobel Laureate Samuel Ting, are already quite spectacular and could only be published so early with the support of the Jülich Supercomputing Centre: cosmic radiation contains far more positrons that expect- ed. Whether this is evidence of another mysterious substance referred to as dark matter is an issue the researchers in the FAME section are planning to explore in the future. The Jülich Electric Dipole Moment Investigation (JEDI) project addresses the second question. Today, although we are aware of phenomena that go some way towards explaining the matter-antimatter asymmetry, these are by far not sufficient to explain its ex- tent. “Another reason would be the existence of a permanent electric dipole moment (EDM) in protons,” explains Prof. Maier, one of the directors of JARA-FAME. An EDM is usually under- stood to mean that positive and nega- tive charges are spatially separated. Demonstrating this in a proton is a huge challenge. If a proton was as big as the Earth, it would mean finding a separa- tion in the order of magnitude of the diameter of a human hair. The FAME researchers are hoping to determine the EDM with unprecedented precision in storage rings, and thus contribute to solving the fundamental question be- hind our existence. It is one of the great mysteries of science: What happened to the antimatter that was creat- ed together with matter at the dawn of the universe? Researchers in the new JARA section FAME (Forces and Matter Experiments) are hoping to unravel this mystery. JARA-FAME: Discovering Elementary Building Blocks and Forces

Forschungszentrum Jülich - Annual Report 2012

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