TY - JOUR

T1 - Applications of chiral perturbation theory

T2 - Mass formulas and the decay 3

AU - Langacker, Paul George

AU - Pagels, Heinz

PY - 1974/1/1

Y1 - 1974/1/1

N2 - Several new results on the breaking of chiral SU(3) × SU(3) are presented within the theoretical framework of chiral perturbation theory. (a) The leading-order corrections to the Gell-Mann-Okubo formula for the baryon octet are shown to be of order 32, where is a chiral symmetry breaking parameter. An explicit exact expression is given for the leading-order corrections, which provides a new development in understanding why this formula works so well. Similarly the corrections to the Gell-Mann-Okubo formula for the ground-state pseudoscalar octet are shown to be of order 2ln (including - mixing). On the basis of these exact results it is argued that SU(3) × SU(3) symmetry is as good as SU(3) symmetry 30% except when one considers electromagnetic interactions. (b) We examine the 3 decay on the assumption that it is regulated by a nonelectromagnetic isospinviolating term of the type 3u3 with u3 a member of 3333. The strength 3 of this term is related to the experimental rate including all leading-order chiral-symmetry corrections. This estimate of 3 leads to I=1 hadron level shifts about a factor of 2 or 3 too large, although our estimate of 3 depends sensitively on the experimental details. (c) Octet enhancement, an exact formalism to describe - mixing, and other topics are discussed.

AB - Several new results on the breaking of chiral SU(3) × SU(3) are presented within the theoretical framework of chiral perturbation theory. (a) The leading-order corrections to the Gell-Mann-Okubo formula for the baryon octet are shown to be of order 32, where is a chiral symmetry breaking parameter. An explicit exact expression is given for the leading-order corrections, which provides a new development in understanding why this formula works so well. Similarly the corrections to the Gell-Mann-Okubo formula for the ground-state pseudoscalar octet are shown to be of order 2ln (including - mixing). On the basis of these exact results it is argued that SU(3) × SU(3) symmetry is as good as SU(3) symmetry 30% except when one considers electromagnetic interactions. (b) We examine the 3 decay on the assumption that it is regulated by a nonelectromagnetic isospinviolating term of the type 3u3 with u3 a member of 3333. The strength 3 of this term is related to the experimental rate including all leading-order chiral-symmetry corrections. This estimate of 3 leads to I=1 hadron level shifts about a factor of 2 or 3 too large, although our estimate of 3 depends sensitively on the experimental details. (c) Octet enhancement, an exact formalism to describe - mixing, and other topics are discussed.

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U2 - 10.1103/PhysRevD.10.2904

DO - 10.1103/PhysRevD.10.2904

M3 - Article

AN - SCOPUS:4243428354

SN - 1550-7998

VL - 10

SP - 2904

EP - 2917

JO - Physical Review D - Particles, Fields, Gravitation and Cosmology

JF - Physical Review D - Particles, Fields, Gravitation and Cosmology

IS - 9

ER -