Physics + Math

23
Jan

Where’s All the Antimatter? New Anti-Atom Beam May Hold the Answer

When the universe burst into existence, according to the Big Bang theory, a colossal explosion released all the matter in the universe. But it also created antimatter, the mysterious doppelgänger of the stuff you and I can see. The British physicist Paul Dirac discovered antimatter in 1928; he asserted that every particle has an “antiparticle” with nearly identical properties, except for an opposite electric charge. When matter meets up with its antimatter counterpart, they obliterate each other in a flash of energy.

antiproton_decelerator
Every component of the Antiproton Decelerator is essential to discovering the mysteries of antimatter.

But here’s the conundrum: the laws of physics also require that matter and antimatter be created in pairs. Accordingly, the Big Bang would have had to produce equal parts matter and antimatter—but that’s not what we see in the universe today. What puzzles scientists is why we have such an abundance of matter and an apparent dearth of its twin.

That’s where a new antimatter beam built at CERN fits in. Experts at the research facility in Geneva, Switzerland want to use it to learn how this disparity happened and what it means.

Scientists have been observing and manipulating antimatter for years. But they haven’t gotten a good look at it because what’s needed to keep the anti-atoms from smashing into regular atoms—a magnetic field—easily confounds the detectors. Measuring anti-particles inside a magnetic field requires carefully eliminating the effects of that field—not an easy task.

To make it work, CERN scientists started with hydrogen, the simplest atom in existence. To make anti-hydrogen, they combined antiprotons with antielectrons using an Antiproton Decelerator. Then, unlike with previous experiments, they used the magnetic field not to contain the antimatter, but direct it away from the strongest magnetic distortion so the spectra, or electromagnetic radiation, could be more accurately measured.

Lead scientist Yasunori Yamazaki in a statement for CERN:

Our results are very promising for high-precision studies of antihydrogen atoms, particularly the hyperfine structure, one of the two best known spectroscopic properties of hydrogen. Its measurement in antihydrogen will allow the most sensitive test of matter/antimatter symmetry.

Yamazaki and his team report producing a beam that consisted of at least 80 antihydrogen atoms stretching for 8.9 feet. It’s an unprecedented level of manipulation, one that physicists hope will help them better understand antimatter and, ultimately, the universe.

This beam could be the foundation of a whole new world of new discoveries. The scientists can now begin to use this beam to perform experiments that test the properties of antimatter. With this ability to create such tangible antiatoms, and the current detail of knowledge that scientists know about the functions and properties of matter, our unanswered questions about the universe’s comparatively scarce antimatter are starting to have a foreseeable future.