Related papers: Do the QCD sum rules support four-quark states?
Despite the apparent simplicity of meson spectroscopy, light scalar mesons cannot be accommodated in the usual $q\bar q$ structure. We study the description of the scalar mesons below 2 GeV in terms of the mixing of a chiral nonet of…
In order to investigate the possibility of the recently observed $X(5568)$ being a $0^{+}$ tetraquark state, we make an improvement to the study of the related various configuration states in the framework of the QCD sum rules.…
The $J/\psi \pi\to \bar{D} D^*, \bar{D} D$, ${\bar D}^* D^*$ and ${\bar D} D^*$ cross sections as a function of $\sqrt{s}$ are evaluated in a QCD sum rule calculation. We study the Borel sum rule for the four point function involving…
In this work, we extend our previous work on the $D^*\bar{D}^*$ molecular states with the $J^{PC}=0^{++}$, $1^{+-}$ and $2^{++}$ to investigate their two-body strong decays via the QCD sum rules based on rigorous quark-hadron duality. We…
In this article, we study the axialvector-diquark-axialvector-antidiquark type scalar, axialvector, tensor and vector $ss\bar{s}\bar{s}$ tetraquark states with the QCD sum rules. The predicted mass $m_{X}=2.08\pm0.12\,\rm{GeV}$ for the…
We apply the method of QCD sum rules to study the doubly heavy tetraquark states $QQ\bar{q}\bar{n}$ with spin-parity $J^{P}=1^{+}$ and strangeness $S=0, -1$ using careful estimates of the Borel and threshold parameters involved. Masses of…
Recently, in Hilger et al. (2011) [1] QCD sum rules for chiral partners in the open-charm meson sector have been presented at nonzero baryon net density or temperature up to and including mass dimension 5. Referring to this, details…
We study light scalar mesons with particular focus on the a_0(980) using lattice QCD with 2+1+1 dynamical quark flavors. To investigate the structure of these scalar mesons and to identify, whether a sizeable tetraquark component is…
The QCD sum rule approach is used to analyze the nature of the rencently observed new resonance $X(4350)$, which is assumed to be a diquark-antidiquark state $[cs][\bar{c}\bar{s}]$ with $J^{PC}=1^{-+}$. The interpolating current…
In this article, we study the $J^{PC}=0^{++}$ and $2^{++}$ $QQ\bar{Q}\bar{Q}$ tetraquark states with the QCD sum rules, and obtain the predictions $M_{X(cc\bar{c}\bar{c},0^{++})} =5.99\pm0.08\,\rm{GeV}$, $M_{X(cc\bar{c}\bar{c},2^{++})}…
In this article, we study the masses and pole residues of the pseudoscalar-diquark-pseudoscalar-antidiquark type and vector-diquark-vector-antidiquark type scalar hidden-charm $cu\bar{c}\bar{d}$ ($cu\bar{c}\bar{s}$) tetraquark states with…
In this article, we construct the diquark-antidiquark type current operators to study the axialvector $B_c$-like tetraquark states with the QCD sum rules. In calculations, we take the energy scale formula as a powerful constraint to choose…
In this work, we take all the color-antitriplet diquarks, such as the scalar, pseudoscalar, vector, axialvector and tensor diquarks, as the basic constituents to construct the local pseudoscalar four-quark currents without importing the…
This talk summarizes the study of the dynamics of the heavy-light \bar Qq open charm and beauty mesons obtained in [1] using QCD spectral sum rules (QSSR) and motivated by the recent experimental discovery of the D{sJ}(2317) and D{sJ}(2457)…
We review our estimations on the light scalar $\bar{q}q$, $(\bar{q}q')(\bar{q'}q)$ and $\overline{qq'}qq'$ ($q,q'\equiv u,d,s$) states from relativistic Laplace sum rule (LSR) within stability criteria and including higher order…
In this paper, we study the $0^{+}$ nonet mesons as tetraquark states with interpolating currents induced from the color-magnetic wavefunction. This wavefunction is the eigenfunction of effective color-magnetic Hamiltonian with the lowest…
Properties of doubly charged scalar tetraquarks $bb\overline{c}\overline{c}$ are investigated in the framework of the QCD sum rule method. We model them as diquark-antidiquark states $X_{\mathrm{1}}$ and $X_{\mathrm{2}}$ built of…
The light scalar meson sigma(600) is known to appear at low excitation energy with very large width on top of continuum states. We investigate it in the QCD sum rule as an example of resonance structures appearing above the corresponding…
Four-quark states are discussed within the constituent quark model. Incompleteness of existed studies of four-quark state with QCD sum rule is analyzed. The masses of diquark cluster were determined by QCD sum rules, and light four-quark…
In this work, we chose three molecular and three diquark-antidiquark currents with the quark content $c\bar{c}s\bar{s}$ and $J^{PC}=0^{++},1^{++},2^{++}$, and estimated the masses and the meson coupling constants of the ground states…