Highly excited mesons, linear Regge trajectories, and the pattern of the chiral symmetry realization

Journal Article · Fri Feb 01 04:00:00 EST 2008 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.77.034002· OSTI ID:21039017

Shifman, M; Vainshtein, A ^[1]

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1. William I. Fine Theoretical Physics Institute, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

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 raised as to whether the linear realization of the chiral symmetry is asymptotically restored for highly excited states. We address it in a number of ways. On the phenomenological side we argue that to the extent the meson Regge trajectories are observed to be linear and equidistant, the Weyl-Wigner mode is not realized. This picture is supported by quasiclassical arguments implying that the quark spin interactions in high excitations are weak, the trajectories are linear, and there is no chiral symmetry restoration. Then we use the string/gauge duality. In the top-down Sakai-Sugimoto construction the nonlinear realization of the chiral symmetry is built in. In the bottom-up AdS/QCD construction by Erlich et al. and Karch et al. the situation is more ambiguous. However, in this approach linearity and equidistance of the Regge trajectories can be naturally implemented, with the chiral symmetry in the Nambu-Goldstone mode. Asymptotic chiral symmetry restoration might be possible if a nonlinearity (convergence) of the Regge trajectories in an 'intermediate window' of n, J, beyond the explored domain, takes place. This would signal the failure of the quasiclassical picture.

• OSTI ID: 21039017
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 3 Vol. 77; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMPTOTIC SOLUTIONS
CHIRAL SYMMETRY
CONVERGENCE
DUALITY
EUCLIDEAN SPACE
EXCITATION
EXCITED STATES
GOLDSTONE BOSONS
MESONS
NONLINEAR PROBLEMS
QUANTUM CHROMODYNAMICS
QUARKS
REGGE TRAJECTORIES
SPIN
WEYL UNIFIED THEORY