Related papers: Second Class Current in QCD Sum Rules
We try to find the grounds for the standard nucleon QCD sum rules, based on more detailed description of QCD vacuum. We calculate the polarization operator of the nucleon current in the instanton medium. The medium (QCD vacuum) is assumed…
I present an overview of the calculations of the isovector axial vector form factor of the nucleon, $G_A(Q^2)$, using lattice QCD. Based on a comparison of results from various collaborations, a case is made that lattice results are now…
We investigate nucleon tensor form factors in the large-$N_{c}$ limit. In this picture, the nucleon emerges as a state of the $N_c$ valence quarks, which were bound by pion mean fields that were created by the presence of the valence quarks…
We perform a complete calculation of charge symmetry breaking effects for the reaction pn -> d pi0 at leading order in chiral perturbation theory. A new leading-order operator is included. From our analysis we extract \delta m_N^{str}, the…
The axial charge g_A is calculated in the epsilon regime of Heavy Baryon Chiral Perturbation Theory to order epsilon^3. To perform this calculation, we develop a technique to compute baryon properties in the epsilon regime of Chiral…
It is shown that the physical ``quark number'' charges which appear in the central charge of the supersymmetry algebra of $N=2$ supersymmetric QCD can take irrational values and depend non trivially on the Higgs expectation value. This…
From the analysis of the recent CCFR data for the \st\ $xF_3(x,Q^2)$ ($0.015<x<0.65$ and $1.2\ GeV^2 < |Q^2| < 501\ GeV^2$) of the deep inelastic neutrino - nucleon scattering we conclude that probably part of the nucleon baryon number is…
We emphasize the role of the x dependence of the quark condensate <|\bar q(0)q(x)|> originated by the zero fermion modes in the instanton vacuum. The effect is not negligible since the inverse size of the instanton 1/\rho~600MeV is…
We generalize forward real Compton amplitude to the case of the interference of the electromagnetic and weak neutral current, formulate a low-energy theorem, relate the new amplitudes to the interference structure functions and obtain a new…
It is known that the trace anomaly in the QCD energy-momentum tensor $T^{\mu \nu}$ can be attributed to the anomalies for each of the gauge-invariant quark part and gluon part of $T^{\mu \nu}$, and their explicit three-loop formulas have…
We construct QCD sum rules for the anti-charmed pentaquark $\Theta_c (3099)$, recently reported at HERA. The sum rules are constructed similarly with the $\Theta^+ (1540)$ sum rules using the anti-charmed analogue of the $\Theta^+$…
The role of the $U(1)_A$ anomaly in QCD phenomenology is reviewed, focusing on the relation between quark dynamics and gluon topology. Topics covered include a generalisation of the Witten-Veneziano formula for the mass of the $\eta'$, the…
Contents: 1. The sum rules or $\Gamma_{p,n}$.Theoretical status. 2. Calculations of matrix elements over the polarized nucleon by the QCD sum rule approach. 3. Twist-4 corrections to $\Gamma_{p,n}$ from QCD sum rules. 4. Gerasimov,…
We argue that quantum electrodynamics combined with quantum gravity results in a new source of CP violation, anomalous non-conservation of chiral charge and quantisation of electric charge. Further phenomenological and cosmological…
The weak charge $Q_W$ measured in atomic parity violation experiments can receive compensating contributions from more than one new physics source. We show explicitly that the $\Delta Q_W$ contribution from the exchange of an extra Z-boson…
The proton's tensor charges are calculated at leading order in a symmetry-preserving truncation of all matter-sector equations relevant to the associated bound-state and scattering problems. In particular, the nucleon three-body bound-state…
We review the progress made in the determination of the weak charge, Q\_w, of the cesium nucleus which raises the status of Atomic Parity Violation measurements to that of a precision electroweak test. Not only is it necessary to have a…
We study the realization of axion electrodynamics in QCD in the presence of a background magnetic field at temperatures high enough for the occurrence of topological charge transitions that are reflected in the presence of a $\theta$-vacuum…
In the effective field theory of quantum gravitation coupled to N_s scalars, N_f fermions, and N_V vectors, tree unitarity is violated at an energy squared of E_{CM}^2 = 20(G_N N)^{-1}, where N = {2/3}N_s + N_f + 4N_V and G_N is Newton's…
Properties of doubly charged scalar tetraquarks $bb\overline{c}\overline{c}$ are investigated in the framework of the QCD sum rule method. We model them as diquark-antidiquark states $X_{\mathrm{1}}$ and $X_{\mathrm{2}}$ built of…