相关论文: Meson-baryon sigma terms in QCD Sum Rules

The nucleon and its negative-parity excited states are examined in a maximum entropy method analysis of QCD sum rules. First, we rederive the parity projected sum rules for baryons using forward correlation functions. Doing this, the method…

We analyze the higher-twist effects and the SU(3)-flavour symmetry breaking in the correlation functions used to calculate form factors of pseudoscalar mesons in the QCD light-cone sum rule approach. It is shown that the Ward identities for…

The pion-nucleon sigma term is shown to be equal to the Goldberger-Treiman discrepancy at tree level. Its value estimated this way is very sensitive to the pion-nucleon coupling constant g_{pi NN}. This relation, when combined with the…

In a recent Physical Review Letter, Kondo and Morimatsu present a QCD sum rule calculation of nucleon-nucleon scattering lengths. They also relate the empirical scattering lengths to the nucleon mass shift in nuclear matter to cast doubt on…

This review article discusses the experimental and theoretical status of various Parton Model sum rules. The basis of the sum rules in perturbative QCD is discussed. Their use in extracting the value of the strong coupling constant is…

We review the DPD sum rules and establish their validity to all orders in QCD. This is done using a diagrammatic approach and light-front perturbation theory. In the process we furthermore investigate the QCD evolution of double parton…

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…

We use QCD sum rules to study the recently observed meson $Z^+(4430)$, considered as a $D^*D_1$ molecule with $J^{P}=0^{-}$. We consider the contributions of condensates up to dimension eight and work at leading order in $\alpha_s$. We get…

We study the QCD phase diagram at finite temperature and baryon chemical potential by relating the behavior of the light-quark condensate to the threshold energy for the onset of perturbative QCD. These parameters are connected to the…

QCD sum rules are used to calculate the contribution of short-distance single-quark transition $s\rightarrow d \gamma$, to the amplitudes of the hyperon radiative decay, $\Omega^-\rightarrow \Xi^-\gamma$. We re-evaluate the Wilson…

We analyze Nf=2 nucleon mass data with respect to their dependence on the pion mass down to mpi = 157 MeV and compare it with predictions from covariant baryon chiral perturbation theory (BChPT). A novel feature of our approach is that we…

We apply the method of QCD sum rules in the presence of external electromagnetic fields $F_{\mu\nu}$ to the problem of the electromagnetic decays of various vector mesons, such as $\rho\to\pi\gamma$, $K^\ast\to K\gamma$ and…

The nuclear density dependencies of the neutron and $\Sigma$ and $\Lambda$ hyperons are important inputs in the determination of the neutron star mass as the appearance of hyperons coming from strong attractions significantly changes the…

We improve our previous QCD sum rule calculation on G(KN\Lambda) and G(KN\Sigma) coupling constants by including the contributions from higher dimensional condensates, <\bar{q} g_s \sigma \cdot G q> and <\bar{q}q> <(\alpha_s /\pi) G^2>, in…

The pion-nucleon sigma term, characterizing the mass component of Higgs origin related to $u$ and $d$ quarks inside the nucleon, is investigated within relativistic baryon chiral perturbation theory at leading two-loop order using the…

Using the light-cone sum rules at leading order, we present an approach to perform the preliminary upper estimation for the nucleon gravitational form factor $D(t)$ ($D$-term contribution). Comparison with the experimental data and with the…

The theoretical evaluation of the coupling constants gpiNN , gKNLambda and gKNSigma is undertaken using QCD sum rules. These quantities were previously calculated with exponential (Borel) kernels used to suppress the unknown contributions…

We give an overview over recent calculations of baryonic correlator functions with finite mass quarks in view on their applicability for QCD sum rules. The QCD sum rule method is then demonstrated within the Heavy Quark Effective Theory.

We demonstrate that the QCD sum rule method can be successfully applied to the calculation of CP-odd electromagnetic observables induced by a vacuum theta--angle. We implement the approach in calculating the electric dipole moment of the…

We analyze new QCD sum rules for the pion wave function $\phi_{\pi}(x)$, obtained recently by A.V. Radyushkin in the framework of the non-local vacuum condensates method for non-diagonal correlators, and suggest a new approach for…