Regge Spectra Research Articles

The sigma meson from QCD sum rules for large- $$N_c$$ N c Regge spectra

The QCD sum rules in the large-$N_c$ limit for the light non-strange vector, axial and scalar mesons are considered assuming a string-like linear spectrum for the radially excited states. We propose a improved method for combined analysis of these channels that gives a reasonable description of the observed spectrum. In the vector-axial case, fixing the pion decay constant and the gluon condensate we obtain more or less physical values for the masses of ground states and the quark condensate. Thus a typical need for this method to fix the mass of some ground state is overcome. Using in the scalar channel the values of presumably universal slope of radial trajectories and the quark condensate obtained in the vector-axial channel, we find that, in contrast to some strong claims in the literature, a prediction of light scalar state with a mass close to the mass of $f_0(500)$ seems to be natural in the considered approach and may follow in a natural way from the Regge phenomenology.

Regge spectra of excited mesons, harmonic confinement, and QCD vacuum structure

An approach to QCD vacuum as a medium describable in terms of statistical ensemble of almost everywhere homogeneous Abelian (anti-)self-dual gluon fields is briefly reviewed. These fields play the role of the confining medium for color charged fields as well as underline the mechanism of realization of chiral $SU_{\rm L}(N_f)\times SU_{\rm R}(N_f)$ and $U_A(1)$ symmetries. Hadronization formalism based on this ensemble leads to manifestly defined quantum effective meson action. Strong, electromagnetic and weak interactions of mesons are represented in the action in terms of nonlocal $n$-point interaction vertices given by the quark-gluon loops averaged over the background ensemble. New systematic results for the mass spectrum and decay constants of radially excited light, heavy-light mesons and heavy quarkonia are presented. Interrelation between the present approach, models based on ideas of soft wall AdS/QCD, light front holographic QCD, and the picture of harmonic confinement is outlined.

A dynamical soft-wall holographic QCD model for chiral symmetry breaking and linear confinement

A self-consistent holographic QCD model is proposed which can realize both chiral symmetry breaking and confinement, two most important phenomena of QCD. It is pointed out that the model can accommodate both Regge spectra of hadrons and the linear potential between quarks. The model is formulated in the framework of graviton-dilaton-scalar system, where the dilaton field is dual to the dimension-2 gluon condensate and can lead to the linear confinement, while the scalar field corresponds to the quark anti-quark condensate and can explain the property of chiral dynamics.

Meson–meson interactions and Regge propagators

By a reformulation of the loop expansion in the Resonance-Spectrum Expansion amplitude for meson–meson scattering, in terms of s-channel exchange of families of propagator modes, we obtain a formalism which allows for a wider range of applications. The connection with the unitarized amplitudes employed in some chiral theories is discussed. We also define an alternative for the Regge spectra and indicate how this may be observed in experiment.

Hadrons in AdS/QCD correspondence

We present an holographical soft wall model which is able to reproduce not only Regge spectra for hadrons with arbitrary integer spin, but also with spin 1/2 and 3/2, and with an arbitrary number of constituents. The model includes the anomalous dimension of operators than create hadrons, together with a dilaton, whose form is suggested by Einstein equations and the AdS metric.

Regge Spectra of Charmed Baryons in Dual Resonance Amplitudes

Regge Spectra of Charmed Baryons in Dual Resonance Amplitudes

Regge spectra, symmetry-breaking effects, and decays of old and new mesons in dual resonance amplitudes

Single-term Veneziano dual amplitudes with nondegenerate Regge slopes are examined in detail. Factorization of parent resonance residues and the equal-spacing rule extracted from the universal-slope case are used to determine all the leading-meson-trajectory parameters in terms of that of the $\ensuremath{\rho}$. Relations between nondegenerate slopes and SU(4)-symmetry-breaking effects are discussed. The predicted meson mass spectra and the partial decay widths into two pseudoscalars are shown to agree well with data for the cases in which data exist.