Related papers: Small size pentaquark width: calculation in QCD su…
Using dimensional regularization for both infrared and ultraviolet divergences, we confirm that the QCD corrections to the decay width $\Gamma(t\to H^+b)$ are equal to those to $\Gamma(t\to W^+b)$ in the limit of a large $t$ quark mass.
In this article, we tentatively assign the $P_c(4312)$ to be the $\bar{D}\Sigma_c$ pentaquark molecular state with the spin-parity $J^P={\frac{1}{2}}^-$, and discuss the factorizable and non-factorizable contributions in the two-point QCD…
In this article, we study the mass spectrum of the scalar hidden charm and bottom tetraquark states with the QCD sum rules. The numerical results are compared with the corresponding ones from a relativistic quark model based on a…
We have used the light-cone formulation of Chiral-Quark Soliton Model to estimate the width of the lightest pentaquark Theta+. We have found that the effect of nonzero momentum transfer is important and reduces drastically the width to…
We compute the renormalization mismatch displayed in 1--loop approximation by classically equivalent 4-quark operators and coming from different possible definitions of the $\gamma_5$ matrix in dimensional regularization. The result is then…
We reanalyze in the first part of this paper the old question of P and CT realization in QCD. The second part is devoted to establish general results on the phase structure of this model in the presence of a $\theta$-vacuum term.
In this work, we determine up/down-quark mass $m_{q=u/d}$ in the isoscalar scalar channel from both the Shifman-Vainshtein-Zakharov (SVZ) and the Monte-Carlo-based QCD sum rules. The relevant spectral function, including the contributions…
Additional broader I=0 states in the KN channel near $\Theta^+$(1540) are expected in many models, making the absence of any signature in the K$^+$-deuteron scattering data even more puzzling. In an ideal "three-body" picture the $\Theta$…
The QCD finite energy sum rules method is used to show that the parameter of the K^0-\bar{K}_0 mixing \hat{B} is mainly determined by the value of g m_s< \bar{d} G_{\mu\nu} \sigma_{\mu\nu} d > and the vacuum expectation values of four-quark…
We use QCD sum rule approach to calculate the masses of the ground-state Lambda_Q and Sigma_Q^(*) baryons. Contributions of the operators up to dimension six are included in operator product expansion. The resulting heavy baryonic masses…
The masses of $uudd\bar s $, $uudd\bar d$, and $uuss\bar d$ pentaquarks are evaluated in a framework of both the Effective Hamiltonian approach to QCD and spinless Salpeter using the Jaffe-Wilczek diquark approximation and the string…
The present status of pentaquark spectroscopy in lattice QCD is reviewed. This talk also includes a brief introduction of pentaquark baryons.
In this letter, we take the point of view that the X(1576) be tetraquark state which consists of a scalar-diquark and an anti-scalar-diquark in relative $P$-wave, and calculate its mass in the framework of the QCD sum rules approach. The…
We propose to increase the factual reliability of descriptions of exotic multiquark hadrons utilizing the approach to bound states of strongly interacting constituents known as QCD sum rules, by allowing exclusively all contributions that…
In this article, we calculate the contributions of the vacuum condensates up to dimension-10 in the operator product expansion, and study the $C\gamma_\mu-C\gamma_\nu$ type scalar, axial-vector and tensor tetraquark states in details with…
The mass and coupling of the scalar tetraquark $T_{bb;\overline{u}\overline{d }}^{-}$ (hereafter $T_{b:\overline{d}}^{-} $) are calculated in the context of the QCD two-point sum rule method. In computations we take into account effects of…
In this work, we study the properties of the pseudoscalar hidden-charm tetraquark states by analyzing their two-body strong decays via the QCD sum rules based on rigorous quark-hadron duality. We take into account the vacuum condensates up…
The relativistic five-quark equations are found in the framework of the dispersion relation technique. The solutions of these equations using the method based on the extraction of the leading singularities of the amplitudes are obtained.…
The $\Theta^+$ Pentaquark is a Very narrow $\Gamma \approx 1$ MeV KN Resonance. Why do some experiments see it and others do not? The lowest quark configuration that can describe it is exotic $uudd \bar s$. Why have no exotics been seen…
A new analysis is performed in QCD sum rule for the lightest negative parity baryon Lambda (1405). Mixings of three-quark and five-quark Fock components are taken into account. Terms containing up to dimension 12 condensates are computed in…