The findings will shape our understanding of the subatomic universe!
Physicists from Syracuse University’s College of Arts and Sciences have made science history by confirming the existence of a rare four-quark subatomic particle, alongside discovering evidence of three more additional “exotic” particles.
The Physicists, Tomasz Skwarnicki and Thomas Britton, both members of the Experimental High-Energy Physics group at SUand the Large Hadron Collider beauty (LHCb) collaboration at CERN, based their confirmation on data provided by the CERN science laboratory in Geneva, Switzerland, which hosts the biggest particle accelerator in the world.
They confirmed the existence of the tetraquark particle, known as X(4140), as well as detected evidence of three other exotic particles, called, X(4274, X(4500) and X(4700).
A tetraquark particle is a particle made of four quarks: two normal quarks and two antiquarks. They are considered to be exotic because they contain an unusual amount of quarks, compared to the more known two or three quark particles. In standard model of particle physics, there exist six kinds of quarks. They are paired into groups based on their intrinsic properties, creating a rather unusual naming system: Up/Down, Charm/Strange and Top/Bottom quarks.
“Even though all four particles contain the same quark composition, each of them has a unique internal structure, mass and set of quantum numbers,” said Skwarnicki in a media release.
The particles in Skwarnicki and Britton’s investigation contain two charm and two strange quarks. These quarks are the third and fourth most massive of all quarks; hence, the four quarks have been grouped into a new family named “Heavy”.
“The heavier the quark, the smaller the corresponding particle it creates,” says Skwarnicki, adding that the names of the particles reflect their masses. “The names are denoted by mega-electron volts [MeV], referring to the amount of energy an electron gains after being accelerated by a volt of electricity. … This information, along with each particle’s quantum numbers, enhances our understanding of the formation of particles and the fundamental structures of matter.”
Providing evidence of the existence of these tetraquark particles hasn’t been an easy task — an “aporetic saga” is how Britton describes studying molecular structures that seem to “jump out of the data.”
“We looked at every known particle and process to make sure that these four structures couldn’t be explained by any pre-existing physics,” he says. “It was like baking a six-dimensional cake with 98 ingredients and no recipe—just a picture of a cake.”
Now, Skwarnicki and Britton must take their findings and comb through the data to develop theoretical models to try and confirm what they found.
“It may be a quartet of entirely new particles or the complex interplay of known particles, simply flipping their identities,” Skwarnicki concludes. “Either way, the outcome will shape our understanding of the subatomic universe.”
The findings formed part of Thomas Britton’s dissertation, which he submitted on behalf of the LHCb collaboration in a journal article to Physical Review Letter (American Physical Society, 2016).
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