Spectroscopy of tetraquark states

• Published in: Physical review. C, Nuclear physics Nuclear physics, 2007-04, Vol.75 (4), Article 045206
• Main Authors: Santopinto, Elena, Galatà, Giuseppe
• Format: Article
• Language: English
• Subjects: A0-980 MESONS; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CLASSIFICATION; COLOR MODEL; DEGREES OF FREEDOM; EIGENVALUES; F0-980 MESONS; FLAVOR; GROUND STATES; NUCLEAR PHYSICS AND RADIATION PHYSICS; OKUBO MASS FORMULA; SPECTROSCOPY; SPIN; WAVE FUNCTIONS
• ISSN: 0556-2813; 1089-490X
• DOI: 10.1103/PhysRevC.75.045206

A complete classification of qqqq tetraquark states in terms of the spin-flavor, color, and spatial degrees of freedom was constructed. The permutation symmetry properties of both the spin-flavor and orbital parts of the qq and qq subsystems are discussed. This complete classification is general and model independent and it is useful both for model builders and experimentalists. The total wave functions are also explicitly constructed in the hypothesis of ideal mixing; this basis for tetraquark states will enable the eigenvalue problem to be solved for a definite dynamical model. An evaluation of the tetraquark spectrum was obtained from the Iachello mass formula for normal mesons, here generalized to tetraquark systems. This mass formula is a generalization of the Gell-Mann Okubo mass formula, whose coefficients have been upgraded by a study of the latest PDG data. The ground-state tetraquark nonet was identified with f{sub 0}(600),{kappa}(800),f{sub 0}(980),a{sub 0}(980). The diquark-antidiquark limit was also studied.