QCD sum rules for the isospin-breaking axial correlator with correct chiral behavior

Journal Article · Mon Sep 01 04:00:00 EDT 1997 · Physical Review, C

DOI:https://doi.org/10.1103/PhysRevC.56.1588· OSTI ID:542322

Maltman, K ^[1]; Birse, M C ^[2]

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1. Department of Mathematics and Statistics, York University, 4700 Keele Street, North York, Ontario, M3J 1P3 (CANADA)
2. Theoretical Physics Group, Department of Physics and Astronomy, University of Manchester, M13 9PL (United Kingdom)

We revisit the QCD sum-rule treatment of the isospin-breaking correlator {l_angle}0{vert_bar}T[A{sub {mu}}{sup 3}(x)A{sub {nu}}{sup 8}(0)]{vert_bar}0{r_angle}, in light of the recent claim that a previous treatment produced results incompatible with known chiral constraints. The source of the error in the previous analysis is identified, and a corrected version of the sum-rule treatment obtained. It is then shown that, using input from chiral perturbation theory, one may use the resulting sum rule to extract information on the leading chiral behavior of isospin-breaking parameters associated with the coupling of excited pseudoscalar resonances to the axial currents. A rather accurate extraction is possible for the case of the {eta}{sup {prime}}. Demanding stability of the sum-rule analysis also allows us to improve the upper bound on the fourth-order low-energy constant, L{sub 7}. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 542322
• Journal Information: Physical Review, C, Journal Name: Physical Review, C Journal Issue: 3 Vol. 56; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CHIRAL SYMMETRY
COUPLING
ISOSPIN
PERTURBATION THEORY
QUANTUM CHROMODYNAMICS
RESONANCE
STABILITY
SUM RULES