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S. S. Afonin

Publications and source records attributed to S. S. Afonin.

81 records · Page 5Linked to original sources

Matching meson resonances to OPE in QCD

We investigate the possible corrections to the linear Regge trajectories for the light-quark meson sector by matching two-point correlators of quark currents to the Operator Product Expansion. We find that the allowed modifications to the linear behavior must decrease rapidly with the principal quantum number. After fitting the lightest states in each channel and certain low-energy constants the whole spectrum for meson masses and residues is obtained in a satisfactory agreement with phenomenology. The perturbative corrections to our results are discussed.

hep-ph↗

Matching Regge Theory to the OPE

The spectra of masses and decay constants for non-strange meson resonances in the energy range 0--2.5 GeV is analyzed. It is known from meson phenomenology that for given quantum numbers these spectra approximately follow linear trajectories with a universal slope. These facts can be understood in terms of an effective string description for QCD. For light meson states the trajectories deviate noticeably from the linear behavior. We investigate the possible corrections to the linear trajectories by matching two-point correlators of quark currents to the Operator Product Expansion (OPE). We find that the allowed modifications to the linear Regge behavior must decrease rapidly with the principal quantum number. After fitting the lightest states in each channel and certain low-energy constants the whole spectrum for meson masses and residues is obtained in a satisfactory agreement with phenomenology. We briefly speculate on possible implications for the QCD effective string.

hep-ph↗

Quark condensate and deviations from string-like behaviour of meson spectra

I analyse the hypothesis that deviations from the linear meson mass spectra appear due to the dynamical chiral symmetry breaking in QCD. It is shown that the linear mass spectrum for the light, non-strange vector and axial-vector mesons is then parametrized by the constant $f_π$, being successful phenomenologically. The toy model for deviations from linearity is proposed.

hep-ph↗

Vector particles in Quasilocal Quark Models

We consider the Quasilocal Quark Model of NJL type including vector and axial-vector four-fermion interaction with derivatives. The mass spectrum for the ground and first excited states is obtained. The chiral symmetry restoration sum rules in these channels are imposed as matching rules to QCD at intermediate energies and a set of constraints on parameters of QQM is performed.

hep-ph↗

Meson mass spectrum and OPE: matching to the large-N_c QCD

The relations between masses and decay constants of variety of meson resonances in the energy range 0--3 GeV are verified from the string-like, linear mass spectrum for vector, axial-vector, scalar and pseudoscalar mesons with a universal slope. The way to match the universality with the Operator Product Expansion (OPE) is proposed. The necessity of small deviations from linearity in parameterization of the meson mass spectrum and their decay constants is proven from matching to OPE.

hep-ph↗

QCD tests for Quasilocal Quark Model

We perform the QCD testing of the Quasilocal Quark Model (QQM) based on Operator Product Expansion (OPE). The quark current correlators calculated in framework of the model, are compared to their OPE in QCD at intermediate energies. The QQM provides a reasonable resolution for mass spectrum of parity doublers in scalar and vector meson channels.

hep-ph↗

Contribution of higher meson resonances to the electromagnetic $π$-meson mass difference

Modifications of the DGMLY relation for calculation of electromagnetic $π$-meson mass difference based on the Chiral Symmetry Restoration phenomenon at high energies as well as the Operator Product Expansion of quark densities for vector ($ρ$) and axial-vector ($a_1$) meson fields difference are proposed. In the calculations higher meson resonances in vector and axial-vector channels are taken into account. It is shown that the inclusion of the first $ρ$ and $a_1$ radial excitations improves the results for electromagnetic $π$-meson mass difference as compared with the previous ones. Estimations on the electromagnetic $ρ$ and $a_1$-meson decay constants and the constant $L_{10}$ of effective chiral Lagrangian are obtained from the generalized Weinberg sum rules.

hep-ph↗

Vector mesons in Quasilocal Quark Models

We consider the Quasilocal Quark Model of NJL type including vector and axial-vector four-fermion interaction with derivatives. In the presence of a strong attraction in the scalar channel the chiral symmetry is spontaneously broken and as a consequence the composite meson states are generated in the vector and axial-vector channels. The appropriate set of Chiral Symmetry Restoration Sum Rules in these channels are imposed as matching rules to QCD at intermediate energies. The mass spectrum and some decay constants for ground and excited meson states are calculated.

hep-ph↗