Named "Sigma-sub-b" particles, the two exotic and incredibly quick to decompose particles are like rare jewels mined from mountains of data, said team leader Petar Maksimovic, assistant professor of physics and astronomy in the university's Krieger School of Arts and Sciences.
"These particles are members of what we call the 'baryonic' family, so-called for the Greek word 'barys,' which means heavy," Maksimovic said. "Baryons are particles that contain three quarks, which are the fundamental building blocks of matter."
The simplest baryons are the proton and neutron, which make up the nuclei of atoms of ordinary matter. "These newest members of that family are unstable and ephemeral, but they help us to understand the forces that bind quarks together into matter," Maksimovic said.
Containing the second-heaviest quark – called "the bottom quark" – the new particles are the heaviest baryons found yet: heavier even than a complete helium atom, which has two protons, though lighter than a lithium atom, which has three.
How rare is Sigma-sub-b? The team combed through a hundred trillion proton-antiproton collisions at the Tevatron, the world's most powerful particle accelerator, to find about 240 Sigma-sub-b candidates, Maksimovic said. The new particles are extremely short-lived, decaying within a tiny fraction of a second.
"Little by little, we are compiling an ever-clearer picture of how quarks build matter and how subatomic forces hold quarks together and tear them apart," said Maksimovic, who noted that the discovery -- confirming the expectation of theorists that Sigma-sub-b particles exist -- helps complete the so-called "periodic table of baryons."
There are six different types of quarks: up, down, strange, charm, bottom and top (u, d, s, c, b and t). One of the new baryons discovered by the CDF experiment is made of two up quarks and one bottom quark (u-u-b), the other of two down quarks and a bottom quark (d-d-b). For comparison, protons are u-u-d combinations, while neutrons are d-d-u.
The Tevatron collider helped the team of physicists to recreate the conditions present in the early formation of the universe, reproducing the exotic matter that was abundant in the moments after the big bang. While the matter around us is constructed with only up and down quarks, exotic matter contains other quarks as well, according to Maksimovic.
The Tevatron is located at the Department of Energy's Fermi National Accelerator Laboratory, also known as Fermilab, in Batavia, Ill. Led by Maksimovic, the team also included Johns Hopkins graduate student Jennifer Pursley, former undergraduate student Michael Schmidt and post-doctoral fellow Matthew Martin, along with five other scientists from Fermilab and the University of New Mexico. All are members of the collaboration of 700 physicists working on the CDF detector at Fermilab.
The Tevatron accelerates protons and antiprotons close to the speed of light and makes them collide. In the collisions, energy transforms into mass, according to Einstein's famous equation E=mc^2. The odds of producing bottom quarks -- which in turn transform into the Sigma-sub-b, according to the laws of quantum physics -- are extremely low. But scientists were able to beat the low odds by producing billions of collisions in the Tevatron each second.
"It's amazing that scientists can build a particle accelerator that produces this many collisions, and equally amazing that the CDF collaboration was able to develop a particle detector that can measure them all," said CDF co-spokesman Rob Roser of Fermilab. "We are confident that our data hold the secret to even more discoveries that we will find with time."
Lisa DeNike | EurekAlert!
One-way roads for spin currents
23.05.2018 | Singapore University of Technology and Design
Tunable diamond string may hold key to quantum memory
23.05.2018 | Harvard John A. Paulson School of Engineering and Applied Sciences
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
23.05.2018 | Life Sciences
23.05.2018 | Life Sciences
23.05.2018 | Physics and Astronomy