Chromomagnetism, flavour symmetry breaking and S-wave tetraquarks
  The chromomagnetic interaction, with full account for flavour-symmetry breaking, is applied to S-wave configurations containing two quarks and two antiquarks. Phenomenological implications are discussed for light, charmed, charmed and strange, hidden-charm and double-charm mesons, and extended to their analogues with beauty. 
Franco Buccella, Hallstein Hogaasen, Jean-Marc Richard, Paul Sorba