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

Searching for new asymmetry between matter and antimatter

Once a particle of matter, always a particle of matter. Or not. Thanks to a quirk of quantum physics, four known particles made up of two different quarks—such as the electrically neutral D meson composed of a charm quark ...

Mysterious antimatter observed falling down for first time

For the first time, scientists have observed antimatter particles—the mysterious twins of the visible matter all around us—falling downwards due to the effect of gravity, Europe's physics lab CERN announced on Wednesday.

Why does matter exist? Roundness of electrons may hold clues

In the first moments of our universe, countless numbers of protons, neutrons and electrons formed alongside their antimatter counterparts. As the universe expanded and cooled, almost all these matter and antimatter particles ...

Unraveling a mystery surrounding cosmic matter

Early in its history, shortly after the Big Bang, the universe was filled with equal amounts of matter and "antimatter"—particles that are matter counterparts but with opposite charge. But then, as space expanded, the universe ...

Researchers measure rare particle decay with high precision

At CERN's Large Hadron Collider (LHC), studies of rare processes allow scientists to infer the presence of heavy particles, including undiscovered particles, that cannot be directly produced. Such particles are widely anticipated ...

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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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