Large Hadron Collider detects new form of matter

Physicists at the Large Hadron Collider (LHC) have detected a new kind of particle called the pentaquark for the first time. 

Like the elusive Higgs boson before it, the pentaquark has been long theorised but never pinned down until now.

In 1964, two American physicists, Murray Gell Mann and George Zweig, independently proposed the existence of the subatomic particles known as quark in protons and neutrons. When five join together, the result is the pentaquark. 

The search for the exotic particles was like “looking for silhouettes in the dark”, according to CERN. The announcement of the detection of the particle by several teams during the mid-2000s was subsequently undermined by other experiments.

These latest findings open a new pathway in understanding of what holds atomic nuclei together, says Guy Wilkinson, CERN spokesman. "The pentaquark is not just any new particle… It represents a way to aggregate quarks, namely the fundamental constituents of ordinary protons and neutrons, in a pattern that has never been observed before in over fifty years of experimental searches.

"Studying its properties may allow us to understand better how ordinary matter, the protons and neutrons from which we're all made, is constituted."

After millions of hours spent doing maintenance work on the €10 billion collider, the LHC returned into service this year, after a refit and a re-tuning. The LHC’s first phase of operations lasted from 2008 - 2012. In the new phase, the LHC will attain collision energies of twice the force that enabled discovery of the Higgs boson in 2012.