Spectroscopy of tetraquark mesons
Abstract
A classification of tetraquark states in terms of the spin-flavour, colour and spatial degrees of freedom has been constructed. The permutational symmetry properties of both the spin-flavour and orbital parts of the quark-quark and antiquark-antiquark subsystems are briefly discussed. This classification is useful both for model-builders and experimentalists. An evaluation of the tetraquark spectrum is obtained from a Iachello mass formula for tetraquark systems. The ground state tetraquark nonet is identified with
f
0
(600)
,
κ(800)
,
f
0
(980)
,
a
0
(980)
. The mass splittings predicted by this mass formula are in agreement with the KLOE, Fermilab E791 and BES experimental data.