CERN Discovers Two New Particles That Were the Stuff of Myth

CERN just discovered two new particles that scientists thought were the stuff of myth. But in a new breakthrough study, they can now prove that their predictions were correct.

A team leading the LHCb experiment at CERN's Large Hadron Collider (LHC) announced Wednesday the existence of two new subatomic particles in the baryon family: Xi_b'- and Xi_b*-. The particle duo was previously predicted by the quark model but never actually observed until now.

"Nature was kind and gave us two particles for the price of one," Matthew Charles of the CNRS's LPNHE laboratory at Paris VI University, said in a CERN news release. "The Xi_b'^- is very close in mass to the sum of its decay products: if it had been just a little lighter, we wouldn't have seen it at all using the decay signature that we were looking for."

Like protons, the newly discovered particles are baryons, made from three quarks bound together by a strong force. The new X_ib particles both contain one beauty (b), one strange (s), and one down (d) quark, and are more than six times the mass of protons.

In addition to these particles' masses, the researchers also looked at their relative production rates, widths, and levels of instability. Their findings proved to match up with predictions made by the theory of Quantum Chromodynamics (QCD), which is part of the Standard Model of particle physics.

"If we want to find new physics beyond the Standard Model, we need first to have a sharp picture," said LHCb's physics coordinator Patrick Koppenburg from Nikhef Institute in Amsterdam. "Such high precision studies will help us to differentiate between Standard Model effects and anything new or unexpected in the future."

By better understanding the basic building blocks of matter, scientists can gain valuable insight into the world of physics and be able to explain a wide variety of phenomena.

The latest measurements, reported in a paper submitted to the journal Physical Review Letters, were made with the data taken at the LHC during 2011-2012. The LHC is currently shutdown and being revamped to operate at higher energies and with more intense beams. It is scheduled to restart by spring 2015.