Showing papers on "Chiral anomaly published in 1975"

One-loop divergences of the nonlinear chiral theory

Abstract: An application of dimensional renormalization to chiral-invariant theories is presented. The naive Feynman rules may be used in this framework without introducing any noninvariant corrections to the on-mass-shell S matrix in the one-loop approximation. Moreover, the soft-pion theorem is fulfilled in all orders of perturbation theory. (AIP)

Chiral symmetry and the quark model

Abstract: The construction of chiral-symmetric quark models is investigated. We show that the Nambu-Goldstone realization of chiral symmetry leads naturally to representation mixing of quark states and of their composites. Constructing SU(6) wave functions for hadron states, we obtain a mixing scheme algebraically equivalent to the Melosh transformation. The resulting phenomenology for pionic decays and for weak and electromagnetic vertices is known to be very successful. The present work provides a theoretical basis for these results and opens new avenues for the study of SU(6) symmetry and the investigation of deep-inelastic scattering processes.

A Dual Picture for Meson Resonances in Terms of Two Limiting Symmetries

Abstract: On the basis of lightlike chiral algebra, axial charge couplings of meson resonances are studied in terrhs of the two limiting symmetries, SU(6) 8 ®0(3)L and chiral SU(3)®SU(3). By the help of sum rules it is argued that the coexistence of SU(6) and chiral couplings attributes the breaking of one symmetry to the leakage through couplings of the other. Experimental check of this dual picture is made, though it is not conclusive due to the lack of crucial information. The concept of constituent quarks is also discussed in the lightlike formulation. § I. Introduction In previous two articles 1> we investigated a lightlike formulation of the quark model for hadrons. We studied the general structure of axial charge couplings on the non-exoticity assumption, and derived ·SUm rules of Adler-Weisberger type for lightlike chiral contents of hadron resonances. All the arguments were made without recourse to any symmetry higher than SU(3). The aim of this article is to discuss how our approach can be concerned with the symmetry pattern of hadrons. This is an important problem for the lightlike formulation, because lightlike chiral algebra•> is characterized by its commutativity with the stability group Y(r), which does not contain p-. It is our basic standpoine> that the non-symmetry nature of SU(3) 1Q!;;SU(3) 1 essentially arises from the spontaneous breakdown of chiral symmetry. 4> The ap­ proximate realization of chiral symmetry through the Goldstone-Nambu mechanism provides us with a ·theoretical basis for the partially conserved axial-current hypoth­ esis.5> By this hypothesis we can relate axial charge couplings to pseudoscalar octet meson (P8) vertices in terms of the relation 8>