Related papers: Exotic Quark Structure of Lambda(1405) in QCD Sum …
We consider the chiral Lagrangian for baryon fields with J^P =\frac{1}{2}^+ or J^P =\frac{3}{2}^+ quantum numbers as constructed from QCD with up, down and strange quarks. The specific class of counter terms that are of chiral order Q^3 and…
Applications of QCD sum-rule methods to the physics of nuclei are reviewed, with an emphasis on calculations of baryon self-energies in infinite nuclear matter. The sum-rule approach relates spectral properties of hadrons propagating in the…
In this article, we restudy the mass spectrum of the ground state triply-heavy baryon states with the QCD sum rules by carrying out the operator product expansion up to the vacuum condensates of dimension 6 in a consistent way and…
We emphasize the role of the x dependence of the quark condensate <|\bar q(0)q(x)|> originated by the zero fermion modes in the instanton vacuum. The effect is not negligible since the inverse size of the instanton 1/\rho~600MeV is…
The four-quark condensates appearing in QCD sum rule are calculated nonperturbatively in a realistic QCD motivated extended Nambu-Jona-Lasinio model. The calculation is in the framework of the effective potential for local composite…
In addition to the conventional $q\bar{q}$ and $qqq$ bound states of quarks $q$, exotic hadrons, such as the four-quark $q\bar{q}q\bar{q}$ and the five-quark $qqqq\bar{q}$ bound states, can be constructed by assuming colour confinement in…
The QCD sum rule method is formulated for the strangeness +1 pentaquark baryon with isospin I=0 and spin-parity J^P = 3/2^\pm. The spin-3/2 states are considered to be narrower than the spin-1/2 ones, and thus may provide a natural…
The baryon self-energies are expressed in terms of the QCD condensates of the lowest dimension in symmetric and asymmetric nuclear matter within the QCD sum-rule approach. The self-energies are shown to satisfy the Gell-Mann--Okubo…
The flavor and spin structure for the quark distributions of the $\Lambda$-baryon is studied in a perturbative QCD (pQCD) analysis and in the SU(6) quark-diquark model, and then applied to calculate the $\Lambda$-polarization of…
It has been suggested to use the production of Lambda hyperons for investigating the nucleon spin structure. The viability of this idea depends crucially on the spin structure of the Lambda. Using nonperturbatively O(a) improved Wilson…
The nature of the Lambda(1405), and its place in the baryon spectrum has remained uncertain for decades. Theoretical studies have shown that it may possess strong dynamical components which are not seen in other well-known baryons. Using…
With the experimental observation of several credible candidates for multiquark hadrons, the latter states re-entered the focus of interest of theoretical strong-interaction physics. Proper treatment of hadronic bound states by quantum…
The NKY coupling constant for $Y = \Lambda$ and $\Sigma$ is evaluated in a QCD sum rule calculation. We discuss and extend the result of a previous analysis in the $\rlap{/}{q}i\gamma_5$ structure and compare it with the result obtained…
In this article, we recalculate the contributions of all vacuum condensates up to dimension-6, in particular the one-loop corrections to the quark condensates $\alpha_s<\bar{q}q>$ and partial one-loop corrections to the four-quark…
We analyze the so-called pinched weights, that are generally thought to reduce the violation of quark-hadron duality in Finite-Energy Sum Rules. After showing how this is not true in general, we explain how to address this question for the…
Wilson coefficients of light four-quark condensates in QCD sum rules are evaluated for pseudo-scalar $D$ mesons, thus, pushing the sum rules toward mass dimension six. Contrary to the situation for $\bar{q}q$ mesons the impact of the…
With the use of the world-line formalism, the heavy-quark condensate in the SU(N)-QCD is evaluated for the cases when the next-to-1/r term in the quark-antiquark potential at short distances is either quadratic, or linear. In the former…
Low-lying $\Lambda$ baryons with spin 1/2 are analyzed in full (unquenched) lattice QCD. We construct $2 \times 2$ cross correlators from flavor SU(3) "octet" and "singlet" baryon operators, and diagonalize them so as to extract information…
We apply the method of QCD sum rules to study the structure $X$ newly observed by the BESIII Collaboration in the $\phi \eta^\prime$ mass spectrum in 2.0-2.1 GeV region in the $J/\psi \rightarrow \phi \eta \eta^\prime$ decay. We construct…
We complete the non-perturbative calculations of the strange quark mass and the Lambda parameter in two flavor QCD by the ALPHA collaboration. The missing lattice scale is determined via the kaon decay constant, for whose chiral…