Manufacturing Bits: Jan. 18

Proton/antiproton measurements; charmed quarks.


Proton/antiproton measurements
CERN, the European Organization for Nuclear Research, has made a breakthrough in particle physics by conducting the world’s most precise measurements and comparisons between protons and antiprotons.

The breakthrough can help scientists gain a better understand of particle physics as well as the origins and the composition of the universe. It can also bring new insights how matter is formed in materials.

In simple terms, an atom is the smallest unit of matter. Each atom consists of a nucleus and one or more electrons. The atomic nucleus consists of protons and neutrons. For every particle, there exists a corresponding antiparticle, which matches the particle but with opposite charge, according to CERN. For example, antiprotons are the antimatter counterparts of protons.

When matter and antimatter are in contact, they annihilate each other into pure energy, according to CERN and Syracuse University.

There are broader implications here. In theory, the Big Bang should have created the same of amount of matter and antimatter in the universe. The Big Bang theory, the leading explanation for the origins of the universe, “started with an infinitely hot and dense single point that inflated and stretched at high speeds,” according to, a web site.

But today, there is more matter than antimatter in the universe. Researchers from CERN and other organizations want to know why.

The Baryon Antibaryon Symmetry Experiment (BASE) at CERN hopes to unravel this mystery using its Antiproton Decelerator, a system that produces low-energy antiprotons. The system slows down antiprotons, enabling researchers to study their properties. “Any measured difference between the masses, charges, lifetimes or magnetic moments of matter and antimatter could contribute to understanding why there is more matter than antimatter in the universe,” according to CERN.

Using the Antiproton Decelerator, researchers measured the electric charge-to-mass ratios of the proton and the antiproton with record precision. The results found the electric charge-to-mass ratios are identical to within an experimental uncertainty of 16 parts per trillion, according to CERN.

Researchers are still in the process of understanding why there is more matter than antimatter in the universe. But this experiment takes one step towards unraveling the mystery. “This result represents the most precise direct test of a fundamental symmetry between matter and antimatter, performed with particles made of three quarks, known as baryons, and their antiparticles,” said Stefan Ulmer of the BASE collaboration at CERN.

“This result is four times more precise than the previous best comparison between these ratios, and the charge-to-mass ratio is now the most precisely measured property of the antiproton,” said Ulmer. “To reach this precision, we made considerable upgrades to the experiment and carried out the measurements when the antimatter factory was closed down, using our reservoir of antiprotons, which can store antiprotons for years.”

Charmed quarks
Using two powerful supercomputers, Riken has predicted the existence of an exotic six-quark particle, an event that could shed light on how matter is formed.

As stated, each atom consists of a nucleus and one or more electrons. The atomic nucleus consists of protons and neutrons. Both protons and neutrons are composed of even smaller sub-atomic particles called quarks.

“Quarks are a type of particle that constitute matter,” according to Syracuse University. “There are three pairs (or families) of quarks for a total of six. They are: up/down, charm/strange, top/bottom. Each of these quarks has a corresponding anti-quark which is equal in mass yet opposite in all other aspects.”

Both protons and neutrons consist of three quarks each, according to Riken. Particles consisting of three quarks are known as baryons, according to Riken.

Nonetheless, using a pair of supercomputers with large-scale numerical calculations, Riken predicted the existence of an exotic six-quark particle called a charm di-Omega. For this, researchers used the K computer and the HOKUSAI supercomputer.

“We were extremely fortunate to have had access to the supercomputers, which dramatically reduced the cost and time to perform the calculations. But it still took us several years to predict the existence of the charm di-Omega,” said Takuya Sugiura of the Riken Interdisciplinary Theoretical and Mathematical Sciences Program.

“We’re especially interested in interactions between other particles containing charmed quarks,” said Sugiura. “We hope to shed light on the mystery of how quarks combine to form particles and what kind of particles can exist.”

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