Related papers: Instantons and Polarized Structure Functions
Instanton-dyons, also known as instanton-monopoles or instanton-quarks, are topological constituents of the instantons at nonzero temperature and nonzero expectation value of $A_4$. While the interaction between instanton-dyons has been…
In the instanton models the chiral phase transition is driven by a transition from random instanton-antiinstanton liquid and correlated instanton-antiinstanton molecules. So far this phenomenon was studied by numerical simulations, while we…
Flow equations method of continuous unitary transformations is used to eliminate the minimal quark-gluon interaction in the light-front quantized QCD Hamiltonian. The coupled differential equations in the two lowest Fock sectors correspond…
We review the theory and phenomenology of instantons in QCD. After a general overview, we provide a pedagogical introduction to semi-classical methods in quantum mechanics and field theory. The main part of the review summarizes our…
Momentum sum rule can be used as an inequality to estimate the lower and upper bounds of the momentum fractions of quarks and gluons in a model of proton valid in a limited \textit{x} range. We compute such bounds in a self-similarity based…
Effect of the quark intrinsic motion on the proton spin structure functions is demonstrated. It is shown, that the covariant version of the quark-parton model taking into account the orbital motion gives the consistent picture of the proton…
Monopole-like objects have been identified in multiple lattice studies, and there is now a significant amount of literature on their importance in phenomenology. Some analytic indications of their role, however, are still missing. The 't…
We investigate the relevance of the instanton-induced determinantal 't Hooft interaction to the eta-nucleon coupling within the framework of a three-flavor linear sigma model in the OZI-rule-respecting basis. Instantons, in combination with…
We analyze the quark mass dependence of photon gluon fusion in polarized deep inelastic scattering for both the intrinsic and extrinsic gluon distributions of the nucleon. We calculate the effective number of flavors for each of the heavy…
Chiral quark model with a broken-U(3) flavor symmetry can be interpreted as the effective theory of the instanton-dominated non-perturbative QCD. This naturally suggests the possibility of a negative singlet/octet coupling ratio, which has…
Based on simulations of the interacting instanton liquid model (IILM) with three-flavor quarks, we compute the free energy density of the QCD vacuum as a function of the quark condensate. We then evaluate the second derivative of the free…
The spin structure of the system of quasifree fermions having total angular momentum $J=1/2$ is studied in a consistently covariant approach. Within this model the relations between the spin functions are obtained. Their particular cases…
It is shown that the proton spin problem raised by the Ellis-Jaffe sum rule violation does not in conflict with the SU(6) quark model, provided that the relativistic effect from the quark transversal motions, the flavor asymmetry between…
The main objective of this work is to explore the evolution in the structure of the quark-antiquark bound states in going down in the chirally restored phase from the so-called "zero binding points" T_zb to the QCD critical temperature T_c…
In this work, we critically reanalyze the explicit breaking of the Peccei-Quinn global symmetry -- and the corresponding corrections to the QCD axion potential -- induced by gravity. Specifically, we examine the role of gravitational…
The QCD + QED axial anomaly low-energy theorems are applied to estimate the accuracy of an instanton vacuum - based chiral quark model. The low-energy theorems give an exact relation between the matrix elements of the gluon and photon parts…
Instantons play a crucial role in understanding non-perturbative dynamics in quantum field theories, including those with spontaneously broken gauge symmetries. In the broken phase, finite-size instanton-like configurations are no longer…
Instanton-induced deep-inelastic processes are considered. Unlike previous results we calculate nonzero quark modes contribution.
I present some comments on the relationship between the small-$x$ behaviour of the parton (quark and gluon) densities and the scaling violation of the proton structure function $F_{2}(x,Q^{2})$.
We compute the axial vector current, form factor, and coupling for quarks in the instanton liquid model with two light flavors. Non-local current corrections are derived, as required by the effective 't Hooft interaction. We obtain a…