Tetraquarks in the covariant approaches to QFT

par Alexander Kvinikhidze (Tbilisi State University)

jeudi 6 avr. 2023, 16:00 → 17:00 Europe/Paris

Bât.210 - 1er Etage (Salle des Séminaires) (IJCLab)

In Quantum Field Theory (QFT) the number of particles is not conserved. This fact necessitates a careful theoretical definition of an exotic particle. In particular, to define a tetraquark, as a bound state of two quarks and two antiquarks, requires more subtlety than to simply associate it with a pole in the 4-body Green function. The derivation of the general covariant set of coupled equations of QCD describing the tetraquark in terms of a mix of four-quark states and two-quark states will be sketched. Comparison of these equations with existing covariant approaches will be discussed. This derivation is motivated by (i) the possibility of important improvement of currently used equations in massive calculations (ii) mathematical challenges of resolving severe overcounting problem inherent in the covariant equations for

more than two particles. The set of equations unifying existing approaches will be presented. Development of the covariant approaches to the tetraquark physics in the last decade will be discussed.

 

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