Researchers at the CERN Supercollider have found a never-before-seen particle that¡¯s made up of four charm quarks.?
This was discovered by the Large Hadron Collider Beauty (LHCb) project and was announced at a recent seminar at CERN.?
Researchers claim this discovery to be revolutionary and it¡¯s likely to be the first of a previously undiscovered class of particles that physicists have never really come across.?
This discovery will help physicists to better understand quarks -- an elementary particle which is essentially known as the imperative building block of all matter. Quarks normally fuse together to form composite particles, also known as hadrons (these include protons and neutrons).?
This discovery will help them understand how quark fuse themselves together, resulting in the composite structure.
It is no news that quarks combine together in two to three groups to form hadrons. However, theorists have predicted the existence of a four or a five quark hadrons (known as tetraquark and pentaquark respectively) and in the past few years, experiments including the LHCb have confirmed that such unique hadrons do exist.?
Giovanni Passaleva, the outgoing spokesperson of the LHCb collaboration explains, ¡°Particles made up of four quarks are already exotic, and the one we have just discovered is the first to be made up of four heavy quarks of the same type, specifically two charm quarks and two charm antiquarks. Up until now, the LHCb and other experiments had only observed tetraquarks with two heavy quarks at most and none with more than two quarks of the same type.¡±
Chris Parkes from The University of Manchester said in a statement, ¡°Today¡¯s discovery opens another exciting chapter in this scientific book, allowing us to study our theory of matter particles in an extreme case. This particle is an extreme case - it is an exotic-hadron, containing four quarks rather than the two or three in conventional matter particles, and the first to contain heavy quarks."?
He added, "Studying an extreme system allows scientists to stress-test our theories. Through the study of this particle, and the hope that we will discover further particles in this class in this future, we will test our theory of how quarks combine which also governs protons and neutrons."
The team discovered the particle by looking through the data for ¡®bumps¡¯ -- looking for an excess of collision events in an otherwise smooth background of events. Looking at the detail data by the Large Hadron Collider, researchers found the unique bumps in the mass distribution of particles (which consisted of a charm quark and charm antiquark) that indicated the discovery of a new particle.
As was the case with previous tetraquark discoveries, researchers aren¡¯t clear if this one is a ¡®true tetraquark¡¯ -- a system of four quarks tightly fused together, or a pair of two-quark particles. Regardless, the new discovery will help theoretical physicists test models of quantum, chromodynamics.?