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The nonperturbative origin of delta-function singularity in the chirally-odd twist-3 distribution function e(x)

M. Wakamatsu·Y. Ohnishi
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Abstract

We analytically prove that the existence of the delta-function singularity in the chirally-odd twist-3 distribution $e(x)$ of the nucleon is inseparably connected with the nonvanishing quark condensate as a signal of the spontaneous chiral symmetry breaking of the QCD vacuum. This singularity in $e(x)$, which would be observed as a sizable violation of the 1st moment sum rule, is then interpreted as giving a very rare case that the nontrivial vacuum structure of QCD manifests in an observable of a localized QCD excitation, i.e. the nucleon.

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M. Wakamatsu, Y. Ohnishi. 2003-03-03. The nonperturbative origin of delta-function singularity in the chirally-odd twist-3 distribution function e(x). https://doi.org/10.1103/physrevd.67.114011

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