Recent data from Belle show unusually large partial widths Υ(5S) → Υ(1S)ππ and Υ(5S) → Υ(2S)ππ. The Z(4430) narrow resonance also reported by Belle in ψπ spectrum has the properties expected of a c̄cud̄ charged isovector tetraquark T c̄c . The analogous state T b̄b in the bottom sector might mediate anomalously large cascade decays in the Upsilon system, Υ(mS) → T b̄b π → Υ(nS)ππ, with a tetraquark-...

in this paper, using monte carlo fortran code, we have obtained the binding energies for three different systems of diquark–antidiquark in distances from 0.01 to 15 nm. in [0.1 - 15] nm interval, we made use of coulomb potential because in this interval, strong interaction is negligible. we have compared the binding energies of the systems with one another. the results of these comparisons were...

A chiral invariant Lagrangian describing the tetraquark-quarkonia interaction is considered at the leading and subleading order in the large-Nc expansion. Spontaneous chiral symmetry breaking generates mixing of scalar tetraquark and quarkonia states and non-vanishing tetraquark condensates. In particular, the mixing strength is related to the decay strengths of tetraquark states into pseudosca...

We study the manifestly exotic tetraquark D s0 cus̄d̄ and the scalar tetraquark f0 udūd̄ in SU(3)c anisotropic quenched lattice QCD. We adopt the O a -improved Wilson (clover) fermion at β 5 75 on 123 96 with renormalized anisotropy as at 4, and investigate the correlator of the four-quark (4Q) system, cus̄d̄, with various quark masses including the idealized SU(4) f case. For f0 udūd̄ etc., we only ...

In this article, we take the point of view that Y (2175) be a tetraquark state which consists of color octet constituents, and calculate its mass and decay constant within the framework of the QCD sum rule approach. We release standard criterion in the QCD sum rules approach and take more phenomenological analysis, the value of the mass of Y (2175) is consistent with experimental data; there ma...

We review the status of an ongoing long-term lattice investigation of the spectrum and structure of tetraquark candidates. We focus on the light scalar meson a0(980). First steps regarding the study of a possibly existing ccc̄c̄ tetraquark are also outlined.

The recent reported charmed-strange resonance at 2.32 GeV/c suggests a possible multiquark state. Three types of multiquark bound states are reviewed. A previous model-independent variational approach considers a tetraquark with two heavy antiquarks and two light quarks as a heavy antidiquark with the color field of a quark bound to the two light quarks with a wave function like that of a heavy...

In this article, we take the point of view that the Ds(2700) be a tetraquark state, which consists of a scalar diquark and a vector antidiquark, and calculate its mass in the framework of the QCD sum rules approach. The numerical result indicates that the mass of the vector charmed tetraquark state is about MV = 3.75GeV, which is about 1GeV larger than the experimental data. If there are some t...

In this article, we take the point of view that the Ds(2700) be a tetraquark state, which consists of a scalar diquark and a vector antidiquark, and calculate its mass with the QCD sum rules. The numerical result indicates that the mass of the vector charmed tetraquark state is about MV = (3.75±0.18)GeV or MV = (3.71 ± 0.15)GeV from different sum rules, which is about 1GeV larger than the exper...

In this article, we take the point of view that the Y (2175) be a tetraquark state which consists of the color octet constituents, and calculate its mass and decay constant within the framework of the QCD sum rule approach. The value of the Y (2175) is consistent with the experimental data, there may be some tetraquark components in the state Y (2175). The tetraquark states may consist of the c...