I report on a lattice computation of the energy of a system of two light quarks and two static antiquarks as a function of the separation of the static antiquarks. In terms of hadrons such a system corresponds to a pair of B mesons and its energy to the hadronic potential. I present selected results for different isospin, spin and parity combinations of the individual B mesons mainly focusing o...

We identify the newly found Z(4433) with the first radial excitation of the tetraquark basic supermultiplet to which X(3872) and X(3876) belong. Experimental predictions following from this hypothesis are spelled out.

The mass and wave function of a six-quark system with quantum numbers JP=0−, T=0, called d, are calculated. We use a colored diquark-tetraquark cluster model for the six-quark wave function. A constituent quark model Hamiltonian with a two-body confinement potential, and residual one-gluon, one-pion, and one-sigma exchange interactions is used. The complications due to the quark exchange intera...

Very recently, the D0 collaboration has reported the observation of a narrow structure, X(5568), in the decay process X(5568) → B sπ using the 10.4fb−1 data of pp̄ collision at √ s = 1.96 TeV. This structure is of great interest since it is the first hadronic state with four different valence quark flavors, b, s, u, d. In this work, we present a tetraquark interpretation of the X(5568). Based on...

We study the a0 and σ mesons with the overlap fermion in the chiral regime with the pion mass as low as 182MeV in the quenched approximation. After the ηN ghost states are separated, we find that the a0 mass with qq̄ interpolation field to be almost independent of the quark mass in the region below the strange quark mass. The chirally extrapolated results are consistent with a0(1450) being the u...

In this article, we perform a systematic study of the mass spectrum of the vector hidden charm and bottom tetraquark states using the QCD sum rules. PACS number: 12.39.Mk, 12.38.Lg

We discuss the stability of multiquark systems within the recent model of Glozman et al. where the chromomagnetic hyperfine interaction is replaced by pseudoscalar-meson exchange contributions. We find that such an interaction binds a heavy tetraquark systems QQq̄q̄ (Q = c, b and q = u, d) by 0.2− 0.4 GeV. This is at variance with results of previous models where ccq̄q̄ is unstable. 1 e-mail: u2162...

We perform a QCD sum rule analysis for the light tetraquark taken into account the contribution arising from the two pion intermediate state. With the interpolating currents of the different chiral combinations of scalar and pseudoscalar diquarks and without including the form factor in the tetraquark–two pion vertex, it is shown that interpolating current with maximum chirality has a large cou...