Parity doubling in particle physics

Abstract

Parity doubling in excited hadrons is reviewed. Parity degeneracy in hadrons was first experimentally observed 40 years ago. Recently new experimental data on light mesons caused much excitement and renewed interest to the phenomenon, which still remains to be enigmatic. The present retrospective review is an attempt to trace the history of parity doubling phenomenon, thus providing a kind of introduction to the subject. We begin with early approaches of 1960s (Regge theory and dynamical symmetries) and end up with the latest trends (manifestations of broader degeneracies and AdS/QCD). We show the evolution of various ideas about parity doubling. The experimental evidence for this phenomenon is scrutinized in the non-strange sector. Some experiments of 1960s devoted to the search for missing non-strange bosons are re-examined and it is argued that results of these experiments are encouraging from the modern perspective.

Version to appear in Int. J. Mod. Phys. A, 63 pages, 9 figures

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Cited by in corpus (38)

• Baryon spectroscopy
• Highly Excited Mesons, Linear Regge Trajectories and the Pattern of the Chiral Symmetry Realization
• Universal description of radially excited heavy and light vector mesons
• Holographic like models as a five-dimensional rewriting of large-Nc QCD
• First Measurement of the Polarization Observable E in the $\vec{p}(\vec{\gamma },{\pi }^{+})n$ Reaction up to 2.25 GeV
• Scalar-isoscalar states in the large-Nc Regge approach
• Hydrogen like classification for light nonstrange mesons
• Cluster duality
• Glueballs and deconfinement temperature in AdS/QCD
• AdS/QCD models describing a finite number of excited mesons with Regge spectrum
• Conformal symmetry and light flavor baryon spectra
• Towards a theory of bottom-up holographic models for linear Regge trajectories of light mesons
• Implications of the Crystal Barrel data for meson-baryon symmetries
• Parity doubling from Weinberg sum rules
• The Regge trajectories and leptonic widths of the vector $s\bar{s}$ mesons
• Weinberg like sum rules revisited
• The sigma meson from QCD sum rules for large-$N_c$ Regge spectra
• Towards reconciling the holographic and lattice descriptions of radially excited hadrons
• Mass Formula for Light Nonstrange Mesons and Regge Trajectories in Quark Model
• Modelling duality between bound and resonant meson spectra by means of free quantum motions on the de Sitter space time dS4
• Electromagnetic couplings of radially excited light vector mesons from QCD sum rules
• Gluon Excitations and Quark Chiral Symmetry in the Meson Spectrum: an Einbein Solution to the Large Degeneracy Problem of Light Mesons
• Hadrons and Chiral Symmetry
• Stringy excited baryons in holographic QCD
• Parity Doubling as a Tool for Right-handed Current Searches
• Lagrangian alternative to QCD string
• A multiquark approach to excited hadrons and Regge trajectories
• Polarization observables in double neutral pion photoproduction
• The case of equivalence of low and high energy constraints on Regge vector spectrum in AdS/QCD
• The linear radial spectrum of scalar mesons within the QCD sum rules in the planar limit
• About the possibility of five-dimensional effective theories for low-energy QCD
• Experiments needed in Meson and Baryon Spectroscopy
• Relativistic oscillator model with spin for nucleon resonances
• The flavor universality of some mass splittings in hadrons
• Illustrative Model for Parity Doubling of Energy Levels
• Right-handed Currents Searches and Parity Doubling
• Analysis of mass difference of the $\pi$ and $\rho$ with Bethe-Salpeter equation
• Renormalization-Group Invariant Parity-Doublet Model for Nuclear and Neutron-Star Matter