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Calculation of $g_{πNS_{11}}$ and $g_{ηNS_{11}}$ Couplings in QCD Sum Rules

Hungchong Kim·Su Houng Lee
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Abstract

We calculate the coupling constants, $g_{πNS_{11}}$ and $g_{ηNS_{11}}, using QCD sum rules in the presence of an external meson field. A covariant derivative is introduced within the S_{11} interpolating field so that in the nonrelativistic limit the field dominantly reduces to two quarks in the s-wave state and one quark in the p-wave state. Our result for the couplings obtained by further making use of the soft-meson theorem qualitatively agrees with its phenomenological value extracted from the S_{11}(1535) decay width. The prediction for the couplings however depend on the value of quark-gluon condensate, $< {\bar q} g_s σ\cdot {\cal G} q >$, which is also important in the calculation of the S_{11}(1535) mass itself within the sum rule approach.

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Hungchong Kim, Su Houng Lee. 1997-04-17. Calculation of $g_{πNS_{11}}$ and $g_{ηNS_{11}}$ Couplings in QCD Sum Rules. https://doi.org/10.1103/physrevd.56.4278

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