Detecting new particles can shed light on the Big Bang

Newly discovered particles will help scientists unravel the complex law that governs quarks and elementary particles that make up all atoms in the universe.

American scientists at the Fermi Accelerator Laboratory (Fermilab) in Illinois found that a new type of particle is a combination of four basic quarks . Quarks are primary particles that exist as the smallest material and cannot be further subdivided. In nature, quarks are divided into six primary types, distinguished by magnetic moments. New particles are found in the tetraquark category , formed by a combination of four quarks.

Each proton and neutron contain three quarks, the most stable particle group. Mesons produced by two quarks are also common, but the combination of four extremely rare quarks. Scientists working at the Large Hadron Collider (LHC) in Switzerland last year saw the first signs of a pentaquark , a group of 5 quarks that was long predicted but never appeared. .

Tetraquark seeds were first discovered in 2003 in Japan. Since then, physicists have discovered six tetraquark particles. However, this is the first time they have found a tetraquark combination of four different types of quarks."Previous tetraquarks have the same two quarks , " Dmitri Denisov, a member of the research team, told Live Science.

New tetraquark particles are made up of 4 quarks, then decay into two mesons.(Photo: Fermilab).

In a report published in the February 25 issue of Physical Review Letters, the strange tetraquark particle X (5568) can deeply reflect some of the rules on how to combine different types of quarks, the process by which The strongest force in nature controls. The interaction of strong forces is described by complex theory called quantum kinetics . However, it is difficult to predict the interactions of 4 quarks.

"We understand the properties of strong forces but do not understand the interaction process of these forces at large distances ," Denisov said. "Basically, we don't have a standard model to predict how quarks interact when there are 3-4 different types of quarks combined."

Although so far, scientists have not found any particles that make up more than 5 quarks, but theoretically, the number of quarks involved in combinatorics is not limited.

The Tevatron accelerator at Fermilab was deactivated in 2011, but Denisov's team found signs of a new tetraquark particle in the data store from tens of billions of particle collisions created during the 28 years of Tevatron activity.

According to the researchers, the discovery will help them improve their understanding of quarks, which exist almost immediately after the Big Bang at temperatures billions of times higher than the laboratory temperature. In February 2016, researchers at LHC tried to recreate the beginning of the universe, thereby observing the quarks after the Big Bang. They discovered particles that were more like liquids than gases, even though they existed at ultra-high temperatures.

"The jigsaw puzzle is still incomplete but we have added a new piece to what is already available," Denisov said. "Hopefully, there will finally be a theory that explains these observations, allowing us to better understand the quarks and the forces acting between them."