Related papers: Understanding light scalar meson by color-magnetic…
We study the masses of light tetraquark states $ud\bar{u}\bar{d}$ , $us\bar{u}\bar{s}$ and $ss\bar{s}\bar{s}$ with exotic quantum numbers $J^{PC}=2^{+-}$ using the method of QCD sum rules. It is found that there is no tetraquark operator…
The spectra of some 0++ four-quark states, which are composed of \bar qq pairs, are calculated in QCD. The light four-quark states are calculated using the traditional sum rules while four-quark states containing one heavy quark are…
In the framework of QCD Sum Rules we investigate the $q q^\prime \bar{Q} \bar{Q}$ tetraquark structure with quantum number $J^P = 1^+$, which are embedded in two types of configurations, the $[8_c]_{q \bar{Q}} \otimes [8_c]_{q^\prime…
We study the fully-strange tetraquark states with the exotic quantum numbers $J^{PC} = 0^{+-}$ and $2^{+-}$. We construct their corresponding diquark-antidiquark interpolating currents, and apply the QCD sum rule method to calculate both…
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…
In the present work, we construct the diquark-antidiquark type four-quark currents to investigate the mass spectrum of the ground state hidden-charm-hidden-strange tetraquark states with the quantum numbers $J^{PC}=0^{++}$, $1^{+-}$,…
We calculate the electromagnetic multipole moments of the $P_c^+(4380)$ pentaquark by modeling it as the diquark-diquark-antiquark and $\bar D^*\Sigma_c$ molecular state with quantum numbers $J^P = \frac{3}{2}^-$. In particular, the…
We address the question whether the lightest scalar mesons sigma and kappa are tetraquarks. We present a search for possible light tetraquark states with J^PC=0^++ and I=0, 1/2, 3/2, 2 in the dynamical and the quenched lattice simulations…
We use QCD sum rules to study the possible existence of a \Theta c(3250) charmed pentaquark. We consider the contributions of condensates up to dimension-10 and work at leading order in \alpha_s. We obtain m(\Theta c) = (3.21 +/- 0.13) GeV,…
A systematic analysis shows that the main uncertainties in the form factors are due to the twist-3 wave functions of the light mesons in the light-cone QCD sum rules. We propose an improved approach, in which the twist-3 wave functions…
The calculations of masses and decay constants of the radial excitations of light pseudoscalar and scalar mesons within QCD sum rules method are briefly reviewed. The predictions are based on the $1/N_c$-supported model spectra, which…
Very recently, the LHCb Collaboration observed distinct structures with the $cc\bar{c}\bar{c}$ in the $J/\Psi$-pair mass spectrum. In this work, we construct four scalar ($J^{PC} = 0^{++}$) $[8_c]_{Q\bar{Q^\prime}}\otimes [8_c]_{Q^\prime…
The compact tetraquark states with fully heavy quark contents $QQ\bar Q\bar Q$ are studied as the bound states of the diquark-antidiquark within the Bethe-Salpeter framework. The (anti)diquark masses and form factors used are the same as we…
The analysis of the sum rules (for two differentchoices of 5-quark currents) indicate that to explain experimental results it is necessary to have some one-particle lower state (and pentaquark is a reliable candidate to this state) while…
Motivated by the latest discovery of doubly-charmed tetraquark $T^+_{cc}$ by LHCb collaboration, we have studied the magnetic moments of the possible doubly-heavy pentaquark states with quantum numbers $J^P = 1/2^-$ and $J^P = 3/2^-$ within…
In this paper, we consider all P-wave $\Omega_{b}$ states represented by interpolating currents with a derivative and calculate the corresponding masses and pole residues with the method of QCD sum rule. Due to the large uncertainties in…
In this article, we study the axial-vector mesons $Z_b(10610)$ and $Z_b(10650)$ with the $C\gamma_\mu-C\gamma_5$ type and $C\gamma_\mu-C\gamma_\nu$ type interpolating currents respectively by carrying out the operator product expansion to…
We discuss the specific features of extracting properties of the exotic polyquark hadrons (tetraquarks, pentaquarks) compared to the usual hadrons by the QCD sum-rule approach. In the case of the ordinary hadrons, already the one-loop…
In the present work, the triply heavy tetraquarks states $QQ\bar{Q}\bar{q}$ with $Q=(c, b)$ and $q=(u, d, s)$ with all possible quantum numbers are systematically investigated in the framework of the chiral quark model with the resonance…
Within the realm of QCD sum rules, one of the most important areas of application of this nonperturbative approach is the prediction of the decay constants of heavy mesons. However, in spite of the fact that, indisputably, the adopted…