Research Notes

Six of the particles in the Standard Model are quarks. Illustration courtesy of PBS Nova.

A New State of Beauty and Charm

This week, the ATLAS Collaboration at the CERN Large Hadron Collider announced the first observation of a new meson, the B_c(2S). The discovery is the work of PandA members Rui Wang, Konstantin Toms, and Sally Seidel and is the primary subject of Rui's April 2014 dissertion.

Mesons are subatomic particles composed of one quark and one antiquark. The B_c meson is composed of the heavy quarks beauty (also known as bottom) and charm. This is the heaviest meson state of two different quark flavors and the first member of the B_c family to be observed above the ground state.

The observation provides opportunities for testing predictions based on quantum chromodynamics, the theory of the strong force, and may contribute to extraction of the strong interaction potential.

The B_c(2S) is the third particle to be discovered at the LHC. A paper on the discovery has been submitted to Physical Review Letters.

Further information is available at: arxiv.org/abs/1407.1032.