Introduction to Chiral Perturbation Theory

Lowest-lying spin-1/2 and spin-3/2 baryon magnetic moments in chiral perturbation theory

“…Chiral symmetry and its breaking pattern, in combination with the concept of effective field theory first systematically put forward by Weinberg [2] , has led to a low-energy effective theory of QCD-Chiral Perturbation Theory (ChPT) [3][4][5][6][7][8][9][10] . It has long been realized that ChPT may be employed to study SU (3) breaking effects on the MMs of the baryon octet.…”

Three-loop corrections in a covariant effective field theory

“…Therefore, one can analyze the many-body effects order by order. The loop expansion has the advantage that it is fairly easy to separate the local and nonlocal dynamics and analyze their structures [24,25,33,34,35,36,37]. Consideration of the three-loop integrals will help us determine if this is a good expansion scheme or not for QHD.…”

“…The Feynman part describes the propagation of a baryon or an antibaryon; the Density portion describes on-shell propagation of a nucleon while taking the exclusion principle into account. Thus, one can separate the local and nonlocal dynamics, as in [24,25] (see also Infrared Regularization discussions in [33,34,35,36,37]). All of the vacuum loops are parameterized; only the boson exchange between valence nucleons is calculated.…”

“…The loop expansion has been studied in the context of other effective field theories, particularly Chiral Perturbation Theory (ChPT) [33,34,35,36,37,43,44]. The techniques of Infrared Regularization were developed to separate out and absorb the local portions of the loop expansion in ChPT [33,34,35,36,37].…”

“…The techniques of Infrared Regularization were developed to separate out and absorb the local portions of the loop expansion in ChPT [33,34,35,36,37]. More recently, investigations have been conducted to determine the effect of multi-loop correlations in ChPT and to discover the appropriate expansion parameter [43,44].…”