Related papers: Highly Excited Hadrons in QCD and Beyond
It is shown that experimental meson states with spins J=0,1,2,3 in the energy range 1.9 - 2.4 GeV obtained in recent partial wave analysis of proton-antiproton annihilation at LEAR remarkably confirm all predictions of chiral symmetry…
Recent data for highly excited mesons suggest that not only the chiral $SU(2)_L\times SU(2)_R$ symmetry of QCD is restored high in the spectrum but also the $ U(1)_A$ symmetry. This means that it is not a confining interaction in QCD which…
We discuss the mass spectrum of highly-excited nucleon and $\Delta^*$ resonances. The spectrum exhibits parity doublets, pairs of resonances of identical total angular momentum J but of opposite parity. It has been proposed that the parity…
In this contribution I review recent experimental developments in the spectroscopy of higher-mass mesons, especially candidate radial excitations discussed at the WHS99 meeting in Frascati.
The emergence and importance of hidden local symmetry in the structure of hadrons under extreme conditions is discussed. The topics covered are the potentially important role played by an infinite tower of vector mesons encoded in…
Some simple expectations for the quark mass dependence of radial excitation energies of heavy-light hadrons based on consideration of nonrelativistic quantum mechanics are discussed. Experimental and theoretical results are reviewed in…
Progress in extracting the spectrum of excited hadron resonances in lattice QCD Monte Carlo calculations is reviewed and the key issues and challenges in such computations are outlined. The importance of multi-hadron states as simulations…
Over the past few months, the theory of QCD at high density has been advanced considerably. It provides new perspectives on, and controlled realizations of, confinement and chiral symmetry breaking. Here I survey the recent developments,…
We construct a holographic model for baryons in the context of AdS/QCD and study the spin-1/2 nucleon spectra and its couplings to mesons, taking fully account of the effects from the chiral symmetry breaking. A pair of 5D spinors is…
We briefly review motivation and results of the approach to QCD vacuum as a medium describable in terms of statistical ensemble of almost everywhere constant Abelian (anti-)self-dual gluon fields. An overview of the hadronization formalism…
We survey some prospects of identifying further in-medium modifications of hadrons in a strongly interacting medium with respect to ongoing experiment series of the HADES Collaboration and planned experiments of the CBM Collaboration at…
We study radial excitations of pseudoscalar and vector (q bar q) mesons within a chiral approach. We derive a general form for a chiral Lagrangian describing processes involving excited pseudoscalar and vector mesons. The parameters of the…
It is pointed out that the hadron spectroscopy should be a study of the structure of the QCD vacuum, low-energy elementary excitations on top of which are hadrons. Concentrating on the dynamical breaking of the chiral symmetry in the QCD…
Restoration of chiral and $U(1)_A$ symmetries in excited hadrons is reviewed. Implications of the OPE as well as of the semiclassical expansion for this phenomenon are discussed. A solvable model of the 't Hooft type in 3+1 dimensions is…
Progress in extracting the spectrum of excited hadron resonances is reviewed and the key issues and challenges in such computations are outlined. The importance of multi-hadron states as simulations are done with lighter pion masses is…
A large symmetry group is perhaps experimentally observed in excited hadrons which includes the chiral group U(2)_L x U(2)_R as a subgroup. To possess this large symmetry a dynamical model for excited hadrons, presumably a string model,…
The mass and residues of the first radial and orbital excitations of $J=\frac{1}{2}$ baryons containing two heavy quarks (b or c) are calculated within the QCD sum rules method. In calculations, the general forms of the interpolating…
Prompted by the recent surprising results in QCD spectroscopy, we extend the treatment of the constituent quark model showing that mass differences and ratios have the same values when obtained from mesons and baryons. We obtain several new…
Some aspects of two recent papers on parity doubling in the hadronic spectrum and its relation to restoration of linearly realized chiral symmetry are critically discussed.
The chiral symmetry of QCD shows up in the linear Weyl--Wigner mode at short Euclidean distances or at high temperatures. On the other hand, low-lying hadronic states exhibit the nonlinear Nambu--Goldstone mode. An interesting question was…