Related papers: Instanton effects on charmonium states
We study the charmonium spectrum using a complete one gluon exchange approach based on a phenomenological relativistic $q\bar{q}$ potential model with Dirac spinors in momentum space. We use phenomenological screening factors to include…
A new non relativistic quark model to calculate the spectrum of heavy quark mesons is developed. The model is based on an interquark potential interaction that implicitly incorporates screening effects from meson-meson configurations. An…
The effect of direct current component appearance in material with non-additive energy spectrum in the case when two electromagnetic waves with mutually transverse planes of polarization are incident normally on the surface of the sample is…
We study instanton effects on $B \rightarrow X_s\gamma$ decay using the heavy quark effective field theory and the operator product expansion. In the dilute gas approximation the effect is negligibly small. This is in contrast to the result…
It is suggested the modification of traditional potential model, in which nontrivial structure of inside-hadron vacuum condensate is simulated by geometric properties of inside-hadron space. Confinement of quarks is ensured by closed…
It is computed, using instanton methods, the first allowed energy band for the polymer harmonic oscillator. The result is consistent with the band structure of the standard quantum pendulum but with pure point spectrum. An effective…
These are the (twice) extended notes of a set of lectures given at the ``12th Workshop on Hadronic Interactions'' at the IF/UERJ, Rio de Janeiro (31. 5. - 2. 6. 2000). The lectures aim at introducing essential concepts of instanton physics,…
The charmonium potential at non-zero temperature has been studied using gauge configurations with anisotropic lattices and 2+1 dynamical flavors of light sea quarks. We use the HAL QCD time-dependent method developed for the study of…
On the basis of the phenomenological relativistic harmonic models for quarks we have obtained the masses of P wave mesons. The full Hamiltonian used in the investigation has Lorentz scalar + vector confinement potential, along with one…
A large body of evidence from lattice calculations indicates that instantons play a major role in the physics of light hadrons. This evidence is summarized, and recent results concerning the instanton content of the SU(3) vacuum, instanton…
This is a brief summary of our studies of quantum field theories in a special limit in which the instantons are present, the anti-instantons are absent, and the perturbative corrections are reduced to one-loop. We analyze the corresponding…
I explain how instantons break chiral symmetry and how do they bind quarks in baryons. The confining potential is possibly irrelevant for the task.
Nucleon form factors are evaluated in the spacelike region in a light-front framework. Our phenomenological model is based on a relativistic formulation of the Hamiltonian dynamics. The baryon dynamics is solved in the CMS with relativistic…
A general approach to accounting for retardation effects in the long-range (confining) part of the quark-antiquark potential is presented. The charmonium and bottomonium mass spectra are calculated with the systematic account of…
We have investigated the effect of the finite size of the constituent quarks on singlet and triplet nucleon-nucleon potentials, obtained in the framework of the $SU(2)$ nonrelativistic quark model using the resonating group method in the…
We consider non-perturbative superpotentials from world-sheet instantons wrapped on holomorphic genus zero curves in heterotic string theory. These superpotential contributions feature prominently in moduli stabilization and large field…
We study baryon and diquark correlation functions in the framework of an instanton model for the QCD vacuum. The model naturally accomodates a light scalar diquark. As a consequence, the correlation functions for the nucleon and delta are…
A critical discussion is given of the results for baryon electromagnetic and axial form factors obtained from relativistic constituent quark models in the framework of Poincar\'e-invariant quantum mechanics. The primary emphasis lies on the…
Instanton analysis is applied to models B--H of critical dynamics. It is shown that the static instanton of the massless $\phi^{4}$ model determines the large-order asymptotes of the perturbation expansion of these near-equilibrium dynamic…
We consider the gauge neutral matter in the low--energy effective action for string theory compactification on a \cym\ with $(2,2)$ world--sheet supersymmetry. At the classical level these states (the \sing's of $E_6$) correspond to the…