Heavy quark spectroscopy and prediction of bottom baryon masses

QCD describes hadrons as valence quarks in a sea of gluons and q̄q pairs. At distances above ∼ 1 GeV quarks acquire an effective constituent mass due to chiral symmetry breaking. A hadron can then be thought of as a bound state of constituent quarks. In the simplest approximation the hadron mass M is then given by the sum of the masses of its constituent quarks mi, first written down by Sakharov and Zeldovich: