Related papers: Four-quark condensates in open-charm chiral QCD su…
QCD sum rules for chiral partners in the open-charm meson sector are presented at nonzero baryon net density or temperature. We focus on the differences between pseudo-scalar and scalar as well as vector and axial-vector D mesons and derive…
Open charm mesons (pseudo-scalar and scalar as well as axial-vector and vector) propagating or resting in nuclear matter display an enhanced sensitivity to the chiral condensate. This offers new prospects to seek for signals of chiral…
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…
D mesons serve as excellent probes of hot and/or dense strongly interacting matter. They can provide insight into the restoration of chiral symmetry. The chiral condensate as well as other chirally odd condensates, such as certain…
Pseudo-scalar and scalar $D$ mesons are considered within the QCD sum rule approach. We present an analysis of the mass splitting of the pseudo-scalar D - D-bar mesons and the relation to QCD condensates. Weinberg type sum rules are derived…
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…
QCD sum rules for D and B mesons embedded in cold nuclear matter are evaluated. We quantify the mass splitting of D - D-bar and B - B-bar mesons as a function of the nuclear matter density; extrapolated to saturation density it is in the…
QCD finite energy sum rules, together with the latest updated ALEPH data on hadronic decays of the tau-lepton are used in order to determine the vacuum condensates of dimension $d=2$ and $d=4$. These data are also used to check the validity…
The QCD sum rule approach to the in-medium behavior of hadrons is discussed for omega meson, nucleon and D meson. Emphasis is devoted to the impact of four-quark condensates and to order parameters of spontaneous symmetry breaking.
An updated investigation of QCD sum rules for the first two moments of rho meson spectral functions, both in vacuum and in-medium, is performed with emphasis on the role of the scale related to spontaneous chiral symmetry breaking in QCD.…
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…
QCD sum rules serve as tools to investigate changing hadronic properties in a hot and/or dense nuclear medium. The role of chiral symmetry breaking and restoration effects in a medium can be addressed also in the heavy-light meson sector.…
Results are presented of a Monte Carlo simulation of a 2+1 dimensional Gross-Neveu model with SU(2)xSU(2) chiral symmetry at non-zero baryon chemical potential, corresponding to non-zero baryon density. The phenomenon of quark pair…
As an alternative to the two-quark condensate we propose a specific four-quark condensate as an order parameter of chiral symmetry restoration. We show that this four-quark condensate is closer connected to observable quantities. Within a…
The pion-baryon sigma terms and the strange-quark condensates of the octet and the decuplet baryons are calculated by employing the method of quantum chromodynamics (QCD) sum rules. We evaluate the vacuum-to-vacuum transition matrix…
The scalar confinement in QCD is shown to produce the nonzero quark condensate for any current quark mass. Mechanisms for the Chiral Symmetry breaking and for the nonzero quark condensates are revealed. For the light and strange flavors the…
The in-medium masses of the pseudoscalar open charm ($D$, $\bar D$, $D_s$ and $\bar {D_s}$) and open bottom ($B$, $\bar B$, $B_s$ and $\bar {B_s}$) mesons in hot asymmetric strange hadronic matter are studied within a QCD sum rule approach.…
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…
With QCD sum rule evaluations, spectral changes of hadrons inside nuclear matter are considered, which shed light on QCD condensates and thus on the non-perturbative structure of the QCD ground state. For some light quark configurations,…
The quark condensate in nuclear matter contains a term of order $\rho m_\pi$, arising from the contribution of low-momentum virtual pions to the $\pi N$ sigma commutator. Standard treatments of QCD sum rules for a nucleon in matter generate…