Scientists unveil doubly-charmed new particle
AFP
European scientists said Thursday they have discovered a new subatomic particle containing a never-before-seen combination of quarks -- the most basic building blocks of matter, reports AFP.
The particle, a baryon dubbed Xicc++, contains two heavy charm quarks and one up quark, and has about four times the mass of a more familiar baryon -- the proton.
The particle is predicted in the Standard Model of particle physics, and its discovery was not a shock, said Matthew Charles of the LPNHE physics lab in Paris.
He is one of about 800 scientists to attach their names to the discovery by the Large Hadron Collider (LHC) of the European Organisation for Nuclear Research (CERN).
The collider is most famous for discovering the Higgs boson, which confers mass on matter.
The new particle is the first seen with two such heavy quarks, said the team.
There are six types of quark, with exotic names such as charm, strange and beauty. The charm, top and bottom quarks are the heaviest types.
Quarks make up baryons such as protons and neutrons that comprise most of the mass in the known Universe.
Baryons gather together in atoms, which form the molecules that constitute matter.
This type of particle, these doubly-charmed baryons... theyve been quite elusive, Charles told AFP.
From their short-lived existence in the early Universe, none are left today. And to produce them in the lab requires an extreme concentration of energy, such as can be generated by the new, upgraded LHC.
The Xicc++ is an unstable baryon, said Charles. It lives for a very small fraction of a second before decaying into other, lighter particles.
