by Michael Todd
Two new subatomic particles were discovered last year by an international team of researchers, but the particles’ properties had been predicted seven years earlier in a paper authored by York University physics Professor Randy Lewis and Richard Woloshyn, a scientist at the TRIUMF lab in Vancouver. The European Organization for Nuclear Research, known as CERN, used its Large Hadron Collider to make the discoveries.
The new particles are part of the baryon family, which makes them cousins of the familiar proton and neutron. Baryon particles are each made up of three elemental subatomic particles called quarks. They contain a very heavy kind of quark called a “b” quark, sometimes referred to as a “beauty” or “bottom” quark. The specific particles observed are known as Xi_b’- and Xi_b*-.
Lewis and Woloshyn predicted the composition and mass of the new baryons using a computer calculation based on a theory called lattice quantum chromodynamics, which describes the mathematical rules for how quarks behave. ■