Chiral symmetry

Abstract

Broken chiral symmetry has become the basis for a unified treatment of hadronic interactions at low energies. After reviewing mechanisms for spontaneous chiral symmetry breaking, I outline the construction of the low--energy effective field theory of the Standard Model called chiral perturbation theory. The loop expansion and the renormalization procedure for this nonrenormalizable quantum field theory are developed. Evidence for the standard scenario with a large quark condensate is presented, in particular from high--statistics lattice calculations of the meson mass spectrum. Elastic pion--pion scattering is discussed as an example of a complete calculation to O(p^6) in the low--energy expansion. The meson--baryon system is the subject of the last lecture. After a short summary of heavy baryon chiral perturbation theory, a recent analysis of pion--nucleon scattering to O(p^3) is reviewed. Finally, I describe some very recent progress in the chiral approach to the nucleon--nucleon interaction.

47 pages, Latex with lamuphys.sty, 9 figures embedded. To appear in Proc. of 37. Internationale Universitaetswochen fuer Kern- und Teilchenphysik, Schladming, Austria, Feb. 28 - March 7, 1998

References in corpus (13)

• Pion-nucleon scattering in chiral perturbation theory I: Isospin-symmetric case
• A sum rule approach to the violation of Dashen's theorem
• Virtual photons in SU(2) chiral perturbation theory and electromagnetic corrections to $\pi \pi$ scattering
• Pion-pion scattering at low energy
• The potential of effective field theory in NN scattering
• The Vector and Scalar Form Factors of the Pion to Two Loops
• How small can the light quark masses be?
• Two-loop Analysis of Axialvector Current Propagators in Chiral Perturbation Theory
• Corrections to Sirlin's Theorem in $O(p^6)$ Chiral Perturbation Theory
• The strange quark mass from scalar sum rules updated
• Wave function renormalization in heavy baryon chiral perturbation theory
• m_u + m_d from QCD-Hadron Duality
• CP-PACS results for quenched QCD spectrum with the Wilson action

Cited by in corpus (5)

• Renormalization Group and Decoupling in Curved Space: II. The Standard Model and Beyond
• Bogoliubov's Vision: Quasiaverages and Broken Symmetry to Quantum Protectorate and Emergence
• Chiral perturbation theory
• Non-perturbative Propagators, Running Coupling and Dynamical Mass Generation in Ghost-Antighost Symmetric Gauges in QCD
• Effective Field Theories of QCD for Heavy Quarkonia at Finite Temperature