相关论文: Chiral Symmetry of Nucleon Resonances in QCD sum r…
We calculate the nucleon parameters in symmetric nuclear matter employing the QCD sum rules approach. We focus on the average energy per nucleon and study the equilibrium states of the matter. We treat the matter as a relativistic system of…
We propose an extension of the Quantum Chromodynamics (QCD) sum rules, termed the Resonance sum rules (RSR), to access resonance poles in the complex energy plane. By strategically introducing a contour in the complex plane and conformal…
Interpolating fields, used to excite hadrons from the QCD vacuum in nonperturbative field-theoretic investigations of hadron properties, are explored with an emphasis on unconventional nucleon interpolators. The QCD continuum model for…
The in-medium behavior of the nucleon spectral density including self-energies is revisited within the framework of QCD sum rules. Special emphasis is given to the density dependence of four-quark condensates. A complete catalog of…
If connecting properties of a multiquark hadron with those exhibited by its constituents, QCD sum rules inferred along the routes of traditional wisdom necessarily involve contributions not related at all to and thus not presenting…
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…
Two new sum rules for the quark tensor charges of the nucleon are proposed, based on a relation connecting the quark transversity distributions to the quark helicity distributions and the quark model spin distributions, and on the sum rules…
This talk first discusses some aspects of the chiral expansion with three light flavours related to the (non) applicability of the OZI rule. Next, the extension of ChPT to an effective theory of the full standard model is considered. Some…
We discuss the relevance of the scalar modes appearing in chiral theories with spontaneous symmetry breaking such as the NJL model for nuclear matter studies. We show that it depends on the relative role of chiral symmetry breaking and…
We demonstrate that a five quark state of positive parity with an internal P-wave structure - usually pictured as a composite of an antiquark and two diquarks in a P-wave state - can couple to nucleons and Goldstone particles in a chirally…
Three-quark nucleon interpolating fields in QCD have well-defined SU_L(3)*SU_R(3) and U_A(1) chiral transformation properties, viz. [(6,3)+(3,6)], [(3,3_bar)+(3_bar,3)], [(8,1)+(1,8)] and their "mirror" images, Ref.[9]. It has been shown…
We review the chiral variant and invariant components of nucleon masses and its consequence on the chiral restoration in extreme conditions, neutron star matter in particular. We consider a model of linear realization of chiral symmetry…
We investigate the widths of the recently observed charmonium like resonances X(3872), Z(4430) and Z_2(4250) using QCD sum rules. Extending previous analyses regarding these states as diquark-antiquark states or molecules of D mesons, we…
QCD sum rules are based on the Operator Product Expansion of current correlators, and on QCD-hadron duality. An extension of this program to finite temperature is discussed. This allows for a study of deconfinement and chiral-symmetry…
We pursue the analysis of a set of generalized DGMLY sum rules for the electromagnetic chiral parameters at order $e^2p^2$ and discuss implications for effective Lagrangians with resonances. We exploit a formalism in which charge spurions…
We study the structure of local baryon fields using the method of QCD sum rule. We only consider the single baryon fields and calculate their operator product expansions. We find that the octet baryon fields belonging to the chiral…
We revisit the chiral properties of nucleon interpolating currents, and show that of the two leading order currents $j_1$ and $j_2$, only two linear combinations $j_1\pm j_2$ transform covariantly under the anomalous $U(1)_A$ symmetry. As a…
We consider quark-hadron duality relations and QCD sum rules for correlators involving exotic tetraquark currents, here specializing to the case of quark-exchange processes. We point out the differences they exhibit with respect to the…
In this talk we review some recent results from random matrix models as applied to some non-perturbative issues in QCD. All of the issues we will discuss touched upon the important phenomenon related to the spontaneous breaking of chiral…
Gaussian sum-rules relate a QCD prediction to a two-parameter Gaussian-weighted integral of a hadronic spectral function, providing a clear conceptual connection to quark-hadron duality. In contrast to Laplace sum-rules, the Gaussian…