The Large Hadron Collider (LHC), famously engaged in the quest for the
Higgs boson, has turned up a heavier variant of a sub-atomic particle
first discovered a quarter-century ago, scientists reported on Thursday.
The newcomer is called Chi-b(3P), which was uncovered in the debris from
colliding protons, according to research published in the open-access
online journal arxiv. Like the elusive Higgs and the photon, it is a
boson, meaning it is a particle that carries force.
But while the Higgs is not believed to be made of smaller particles, the
Chi-b(3) comprises two relatively heavy particles, the beauty quark and
its anti-quark.
They are bonded by the so-called “strong” force which also causes the atomic nucleus to stick together.
The Chi-b(3P) is a heavier version of a particle that was first observed
around 25 years ago. “The Chi-b(3P) is a particle that was predicted by
many theorists, but was not observed at previous experiments,” said
James Walder, a British physicist quoted by the University of Birmingham
in a press release.
Described by some as the world's largest machine, the LHC is located in a
27-km ring-shaped tunnel near Geneva that straddles the Franco-Swiss
border up to 580 feet below ground.
Streams of protons are fired in opposite, but parallel, directions in the tunnel.
The beams are then bent by powerful magnets so that some of the protons
collide in four giant labs, which are lined with detectors to record the
sub-atomic debris that results.
Finding the Chi-b(3P) is a further test of the powers of the LHC, which
became the world's biggest particle collider when it was completed in
2008.
“Our new measurements are a great way to test theoretical calculations
of the forces that act on fundamental particles, and will move us a step
closer to understanding how the Universe is held together,” said Miram
Watson, a British research fellow working on the CHi-b(3) investigation.
Massive effort
A massive collaborative effort that brings in physicists from around the
world, the LHC has cost more than 6.03 billion Swiss francs.
