Related papers: High Energy Theorems at Large-N
Momentum sum rule in QCD is widely used at high energy colliders. Although the exact form of the confinement potential energy is not known but the confinement potential energy at large distance $r$ can not rise slower than ${\rm ln}(r)$. In…
We review the solutions of O(N) and U(N) quantum field theories in the large $N$ limit and as 1/N expansions, in the case of vector representations. Since invariant composite fields have small fluctuations for large $N$, the method relies…
HQET currents with the quantum numbers of the ground-state baryons are discussed. One-loop anomalous dimensions are calculated, and exact one-loop matching to QCD currents is found. Two-point correlators of these currents are calculated…
In this talk I consider QCD sum rules for the ground state heavy baryons to leading order in $1/m_Q$ and at next-to-leading order in $\alpha_S$ within the context of Heavy Quark Symmetry. The analysis is done at a fixed scale $\mu=1 GeV$.…
Light-cone QCD sum rules are employed to compute the strong coupling constants: g_{B^* B^* pi}, g_{B_1 B_0 pi} and g_{B_1 B^* pi}, where (B,B^*) and (B_0,B_1) are negative and positive parity (0^-,1^-) and (0^+,1^+) \bar qQ doublets. The…
Nonperturbative Wilson coefficients associated with the leading chiral-symmetry-breaking operators in the operator product expansion of the pseudoscalar QCD correlation function are derived. Implementation of the new, instanton-induced…
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 undergoes a deconfining transition at high temperature to a "quark-gluon plasma" phase where hadrons may become unbound. In this work, meson correlation functions at non-zero momentum are studied both in the confined and plasma phases…
In QCD sum rules with external fields, the double dispersion relation is often used to represent the correlation function. In this work, we point out that the double spectral density, when it is determined by successive applications of the…
We use the operator product expansion to derive exact results for the momentum distribution and the static structure factor at high momentum for a jellium model of electrons in both two and three dimensions. It is shown that independent of…
We calculate the vacuum-expectation-value, the meson mass and the meson decay constant to next-to-next-to-leading-order in the chiral expansion for QCD-like theories with general $N_F$ degenerate flavours for the cases with a complex…
We use the Aleph data on vector and axial-vector spectral functions to test simple duality properties of QCD in the large Nc limit, which emerge in the approximation of a minimal hadronic ansatz of a spectrum of narrow states. These duality…
The large-distance asymptotic behavior of the field-field correlators has been computed for one-dimensional impenetrable anyons at finite temperatures. The asymptotic behavior agrees with the predictions of conformal field theory at low…
In QCD with two massless quarks, the chiral phase transition is plausibly in the same universality class as the classical O(4) magnet. To test this hypothesis, critical exponents characterizing the behaviour of universal quantities near the…
We discuss two dimensional $QCD (N_c\to\infty)$ with fermions in the fundamental as well as adjoint representation. We find factorial growth $\sim (g^2N_c\pi)^{2k}\frac{(2k)!(-1)^{k-1}}{(2 \pi)^{2k}}$ in the coefficients of the large order…
In the present work, the temperature dependence of the scalar mesons parameters is investigated in the framework of thermal QCD sum rules. We calculate sigma-pole and the non-resonant two-pion continuum contributions to the spectral…
The gauge invariant two-point correlator for the gluon field strength tensor in analysed by means of the QCD sum rule method. To this end, we make use of a relation of this correlator to a two-point function for a quark-gluon hybrid in the…
We calculate the two-point massless QCD correlator of nonlocal (composite) vector quark currents with chains of fermion one-loop radiative corrections inserted into gluon lines. The correlator depends on the Bjorken fraction $x$ related to…
A novel procedure for extracting hadron characteristics from QCD sum rules, based on effective continuum thresholds (necessary for the implementation of quark-hadron duality) which may depend on the involved momenta and on the Borel…
I describe recent progress towards a theory of the NN force which captures the consequences of QCD's chiral symmetry and the pattern of its breaking, and is formulated as an expansion in a ratio of low and high mass scales, M_{lo}/M_{hi}.…