The discovery was made as part of the Large Hadron Collider beauty Collaboration, a multinational research project aimed at finding and studying new quantum forces and particles. Led by researchers from Syracuse, the project is headquartered at the European Organization for Nuclear Research (CERN) in Geneva, Switzerland, the biggest particle physics laboratory in the world.
In a new paper, scientists working on the LHCb team claim to have discovered a brand new type of particle.
"We’ve confirmed the unambiguous observation of a very exotic state -- something that looks like a particle composed of two quarks and two anti-quarks," explained Tomasz Skwarnicki, one of the paper's lead authors and a specialist in experimental high-energy physics. "The discovery certainly doesn’t fit the traditional quark model. It may give us a new way of looking at strong-interaction physics."
Quarks are hard, point-like building blocks of an atom's nucleus. Never observed in isolation, quarks combine to form compound particles. They most frequently combine three-at-a-time to form a baryon. Protons are best-known known examples of baryons.
When quarks interact with corresponding anti-particles, or anti-quarks -- a particle with the same mass but opposite charges -- they form mesons. Meson compounds are most commonly observed as a byproduct of radioactive decay.
Together mesons and baryons form a classification of observed particle interactions. Ordinary baryons are made up of three quarks, and ordinary mesons feature one quark bound to one anti-quark.
But the new evidence found by LHCb proves the legitimacy of previous experiments showing the likelihood of a different type of hadron, a tetraquark -- featuring two quarks and two anti-quarks.
"This experiment is the clincher, showing that particles made up of two quarks and two anti-quarks actually exist," Skwarnicki said. "There used to be less-clear evidence for the existence of such a particle, with one experiment being questioned by another. Now we know this is an observed structure, instead of some reflection or special feature of the data."