ISOSPIN SYMMETRY BREAKING THROUGH π0–η–η′ MIXING

Mixing of the pseudoscalar mesons is discussed in the quark-flavor basis. The divergences of the axial vector currents which embody the axial vector anomaly, combined with the assumption that the decay constants follow the pattern of particle state mixing in that basis, determine the mixing parameters for given masses of the physical mesons. These mixing parameters are compared with results from other work in some detail. Phenomenological applications of the quark-flavor mixing scheme are presented with particular interest focussed on isospin symmetry breaking which is generated by means of η and η′ admixtures to the pion. Consequences of a possible difference in the basis decay constants fuand fdfor the strength of isospin symmetry breaking are also examined.

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MIXING OF PSEUDOSCALAR MESONS AND ISOSPIN SYMMETRY BREAKING

International Journal of Modern Physics A ◽

10.1142/s0217751x0502149x ◽

2005 ◽

Vol 20 (02n03) ◽

pp. 331-340 ◽

Cited By ~ 12

Author(s):

PETER KROLL

Keyword(s):

Symmetry Breaking ◽

Axial Vector ◽

Particle State ◽

Isospin Symmetry ◽

Decay Constants ◽

Pseudoscalar Mesons ◽

Quark Flavor ◽

Isospin Symmetry Breaking ◽

State Mixing

Mixing of the pseudoscalar mesons is discussed in the quark-flavor basis with the hypothesis that the basis decay constants follow the pattern of particle state mixing. The divergences of the axial vector currents which embody the axial vector anomaly, combined with this hypothesis provide a calculational scheme for the parameters describing the mixing of the π0, η and η′ mesons. Phenomenological applications of this mixing scheme are presented with particular interest focussed on isospin symmetry breaking in QCD estimated as η and η′ admixtures to the pion. In contrast to previous work a possible difference in the basis decay constants fuand fdis considered and consequences of this potentially large effect on the strength of isospin symmetry breaking is discussed.

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DETERMINING THE PARAMETERS OF ηη′ MIXING IN THE FRAMEWORK OF ANOMALOUS WARD IDENTITIES

Modern Physics Letters A ◽

10.1142/s0217732300000165 ◽

2000 ◽

Vol 15 (03) ◽

pp. 167-173

Author(s):

B. BAGCHI ◽

P. BHATTACHARYYA

Keyword(s):

Ward Identities ◽

Decay Constants ◽

Mixing Parameters ◽

Quark Flavor ◽

Flavor Mixing

The solutions of anomalous Ward identities are used to determine the ηη′ mixing parameters θ8 and θ0 and the octet–singlet decay constants f8 and f0 in a U (3) × U (3) framework. Our results are fairly consistent with other recent findings for these quantities. We also enquire into the quark-flavor mixing scheme and obtain estimates for the corresponding decay constants defined in this basis.

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MIRROR MATTER ADMIXTURES IN KL→γγ

Modern Physics Letters A ◽

10.1142/s0217732304015427 ◽

2004 ◽

Vol 19 (40) ◽

pp. 3019-3029

Author(s):

G. SÁNCHEZ-COLÓN ◽

A. GARCÍA

Keyword(s):

Leading Order ◽

Mixing Angle ◽

Decay Constants ◽

The Third ◽

Power Corrections ◽

Mixing Parameters ◽

Quark Flavor ◽

Flavor Mixing ◽

Mirror Matter

Based on possible, albeit tiny, admixtures of mirror matter in ordinary mesons we study the KL→γγ transition. We find that this process can be described with a small SU (3) symmetry breaking of only 3%. We also determine the η–η' mixing angle and the pseudoscalar decay constants. The results for these parameters are consistent with those obtained in the literature. They favor three recent determinations; the first is based on two analytical constraints, the second one based on next-to-leading order power corrections, and the third one on a phenomenological determination of the mixing parameters in the framework of the quark-flavor mixing scheme.

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