相关论文: Nucleon QCD sum rules in nuclear matter including …
We use QCD sum rules to study the possible existence of $QQ-\bar{u}\bar{d}$ mesons, assumed to be a state with $J^{P}=1^{+}$. For definiteness, we work with a current with an axial heavy diquark and a scalar light antidiquark, at leading…
The quark-meson coupling model for nuclear matter, which describes nuclear matter as non-overlapping MIT bags bound by the self-consistent exchange of scalar and vector mesons, is modified by introducing medium modification of the bag…
The nucleon spectral function in nuclear matter fulfills an energy weighted sum rule. Comparing two different realistic potential, these sum rules are studied for Green's functions that are derived self-consistently within the $T$ matrix…
As an example of an application of lattice QCD we describe a computation of four-quark operators in the nucleon. The results are interpreted in a diquark language.
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…
The bounds on the values of gluon, four-quark and quark-gluon condensates are derived from the requirement of consistency of the sum rules for various correlators of the hybrid current $a_{\mu}=g\bar d\gamma_{\rho}\tilde G_{\rho\mu}u$. The…
We calculate expectation values of QCD operators consisting of the products of the four operators of the light quarks corresponding to the scalar, pseudoscalar, vector, pseudovector (axial) and tensor Lorentz structures in the nucleon. All…
The magnitudes of gluon and four-quark condensates are found from the analysis of vector mesons consisting of light quarks (the families of $\rho$ and $\omega$ mesons) in the 3 loops approximation. The QCD model with infinite number of…
We consider the procedure of determination of induced quark condensates in the QCD sum rule approach. It is noted that the previous estimations of this value were very rough. It is shown, that the detailed analyses of this parameter of QCD…
Sum rules for the variation of finite-density spectral density of vector channel with baryon density are derived based on dispersion relations and the operator product expansion. These sum rules may serve as constraints on the…
The properties of nuclear matter are studied using state-of-the-art nucleon-nucleon forces up to fifth order in chiral effective field theory. The equations of state of symmetric nuclear matter and pure neutron matter are calculated in the…
We estimate the nuclear medium modifications of the quark contribution to the bound nucleon spin sum rule, J^{q*}, as well as the separate helicity, \Delta \Sigma*, and the angular momentum, L^{q*}, contributions to J^{q*}. For the…
Hadron properties are studied at hot medium using the quark sigma model. The quark sigma model is extended to include eighth-order of mesonic interactions based on some aspects of quantum chromodynamic (QCD) theory. The extended effective…
We evaluate the $\pi N$ coupling constant using a QCD sum rule based on the pion-to-vacuum matrix element of the correlator of two interpolating nucleon fields. The part of the correlator with Dirac structure $k\llap/\gamma_5$ is used,…
We extend a recent chiral approach to nuclear matter by including the most general (momentum-independent) NN-contact interaction. Iterating this two-parameter contact-vertex with itself and with one-pion exchange the emerging energy per…
A proper way of subtracting the continuum contributions in light-cone QCD sum rules (LCQSR) is demonstrated. Specifically, we calculate the continuum corresponding to a typical OPE appearing in LCQSR by properly combining the double…
The pion-nucleon and kaon-nucleon scattering lengths are studied in the QCD sum rule. We show that the leading and next-to-leading order terms of the OPE give rise to the Tomozawa-Weinberg and sigma terms, respectively. We also show that in…
The proton matrix element of the isovector-scalar density, $<p|\overline{u}u-\overline{d}d|p>/2M_p$, is calculated by evaluating the nucleon current correlation function in an external isovector-scalar field using the QCD sum-rule method.…
To prove the momentum sum rule in the operator product expansion (OPE) in QCD at high energy colliders it is assumed that $<P| {\hat T}^{++}(0)|P>=2(P^+)^2$ where $|P>$ is the momentum eigenstate of the hadron $H$ with momentum $P^\mu$ and…
The mean field description of nuclear matter in the quark-meson coupling model is improved by the inclusion of exchange contributions (Fock terms). The inclusion of Fock terms allows us to explore the momentum dependence of meson-nucleon…