Despite the f0(980) hadron having been discovered half a century ago, the question about its quark content has not been settled: it might be an ordinary quark-antiquark ( qq¯ ) meson, a tetraquark ( qq¯qq¯ ) exotic state, a kaon-antikaon ( KK¯ ) molecule, or a quark-antiquark-gluon ( qq¯g...
