Related topics: cern · atoms · big bang · electrons · universe

AEgIS on track to test freefall of antimatter

It's a fundamental law of physics that even the most ardent science-phobe can define: matter falls down under gravity. But what about antimatter, which has the same mass but opposite electrical charge and spin? According ...

New calculation refines comparison of matter with antimatter

An international collaboration of theoretical physicists—including scientists from the U.S. Department of Energy's (DOE) Brookhaven National Laboratory (BNL) and the RIKEN-BNL Research Center (RBRC)—has published a new ...

NA61/SHINE gives neutrino experiments a helping hand

Neutrinos are the lightest of all the known particles that have mass. Yet their behavior as they travel could help answer one of the greatest puzzles in physics: why the present-day universe is made mostly of matter when ...

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In particle physics, antimatter is the extension of the concept of the antiparticle to matter, where antimatter is composed of antiparticles in the same way that normal matter is composed of particles. For example, an antielectron (a positron, an electron with a positive charge) and an antiproton (a proton with a negative charge) could form an antihydrogen atom in the same way that an electron and a proton form a normal matter hydrogen atom. Furthermore, mixing matter and antimatter would lead to the annihilation of both in the same way that mixing antiparticles and particles does, thus giving rise to high-energy photons (gamma rays) or other particle–antiparticle pairs.

There is considerable speculation as to why the observable universe is apparently almost entirely matter, whether there exist other places that are almost entirely antimatter instead, and what might be possible if antimatter could be harnessed, but at this time the apparent asymmetry of matter and antimatter in the visible universe is one of the greatest unsolved problems in physics. The process by which this asymmetry between particles and antiparticles developed is called baryogenesis.

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