J. Vijande, ∗ A. Valcarce, † and J.-M. Richard ‡ Departamento de F́ısica Atómica, Molecular y Nuclear, Universidad de Valencia (UV) and IFIC (UV-CSIC), Valencia, Spain. Departamento de F́ısica Fundamental, Universidad de Salamanca, 37008 Salamanca, Spain Université de Lyon, Institut de Physique Nucléaire de Lyon, IN2P3-CNRS–UCBL, 4 rue Enrico Fermi, 69622 Villeurbanne, France (Dated: January 29, ...

The existence of a shallow or virtual tetraquark state, c c ū d̄, is discussed. Using the putative masses for the doubly charmed baryons (c c u/c c d) from SELEX, the mass of the c c ū d̄ state is estimated to be about 3.9GeV , only slightly above the DD threshold. The experimental signatures for various c c ū d̄ masses are also discussed. Typeset using REVTEX 1

The color anti-triplet triquark qq̄q̄ is considered as a compact component in the tetraquark structure cqq̄q̄ of exotic Ds mesons. We discuss the mass spectrum and the flavor mixing of the triquarks by using the instanton induced interaction and the one-gluon exchange potentials. As a characteristic property of the triquark, we investigate the isospin violation. It is shown that the flavor 3 (isosi...

We analyze the possibility of heavy-light tetraquark bound states by means of a chiral constituent quark model. The study is done in a variational approach. Special attention is paid to the contribution given by the different terms of the interacting potential and also to the role played by the different color channels. We find a stable state for both qqc̄c̄ and qqb̄b̄ configurations. Possible deca...

In [1] the light scalar meson nonet has been considered within the QCD sum rules approach with the interpolating current consisting of the scalar diquark and the scalar antidiquark. It has been shown that the negative contributions from the operators of dimension 8 are dominant in the sum rules, so that, there is no evidence of the coupling of the above tetraquark current with the light scalar ...

Inspired by the recent observation of $\chi_{c0}(3930)$, $X(4685)$ and $X(4630)$ LHCb Collaboration some exotic resonances such as $X(4350)$, $X(4500)$, etc. several experiment collaborations, $cs\bar{c}\bar{s}$ tetraquark systems with $IJ^{P}=00^+$, $01^+$ $02^+$ are systematically investigated in framework quark delocalization color screening model(QDCSM). Two structures, meson-meson diquark-...

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. We find that such an interaction binds a heavy tetraquark system 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. Contribution to the Workshop “Q...