Restoration of chiral symmetry in excited hadrons

Abstract

Physics of the low-lying and high-lying hadrons in the light flavor sector is reviewed. While the low-lying hadrons are strongly affected by the spontaneous breaking of chiral symmetry, in the high-lying hadrons the chiral symmetry is restored. A manifestation of the chiral symmetry restoration in excited hadrons is a persistence of the chiral multiplet structure in both baryon and meson spectra. Meson and baryon chiral multiplets are classified. A relation between the chiral symmetry restoration and the string picture of excited hadrons is discussed.

Comments: Lectures given at the XLIV Cracow School of Theoretical Physics, Zakopane, Poland, 28.05 - 06.06.2004. It also partly covers lectures given at the school "QCD and Light Hadrons", Beijing, China, September 26 - 30, 2004. 33 pp., LaTeX