Parity doublets in the baryon spectrum Original Research Article

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 both UA(1) and spontaneous SUL(2)×SUR(2) breakings, in the high-lying hadrons these symmetries are restored. A manifestation is a persis- tence of the chiral multiplet structure in both baryon and meson spectra. A fundamental origin of this phenomenon is that effects of quantum fluctuations of both quark and gluon fields must vanish at large n or J and a semiclassical description becomes adequate. A relation between chiral symmetry restoration and the string picture of excited hadrons is discussed.