The mass spectra of all-charm tetraquark states with the [cc][$\bar{c}\bar{c}$] quark configuration are investigated. coulomb plus linear potential is used in conjunction relativistic correction term $\mathcal{O}(\frac{1}{m})$. To determine fitting parameters for tetraquarks [cc][$\bar{c}\bar{c}$], we first calculate charmonia [c$\bar{c}$] and its decay constants ($f^{2}_{P/V}$). We estimated m...

We study the pair description of heavy tetraquark systems $|QQ\overline{Q}\overline{Q}?$ in frame a nonrelativistic potential model. By taking two quark pairs $(Q\overline{Q})$ as colored clusters, four-quark Schr\"odinger equation is reduced to two-pair equation, when inner motion inside can be neglected. Taking into account all Casimir scaling potentials between quarks and using lattice QCD s...

Supposing the Z c (3900) as a charged partner of the X(3872), we use the QCD sum rules techinques in order to obtain the coupling constants of the Z c J/ψ π , Z c ηc ρ + and Z c D D ∗ vertices and the corresponding decay width of these channels. We considered that the Zc(3900) can be described by a tetraquark current with the J = 1 quantum numbers. As a result, we obtained a decay width value i...

Based on the observation that K0(1430) is lighter than its SU3 counterpart, a0(1450), we examine the possibility that these particles, together with f0(1370), f0(1500) and f0(1710), fill a tetraquark recurrence of the sub-GeV 0 nonet mixed with a glueball state. We find the picture to be consistent with the known data about the three f0 resonances, more than the qq̄ hypothesis. Conventional spin...

It is argued that exotic mesons consisting of two quarks and two antiquarks are not ruled out in quantum chromodynamics with a large number N of colors, as generally thought. Tetraquarks of one class are typically long-lived, with decay rates proportional to 1/N.