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Chiral Symmetry and Diffractive Neutral Pion Photo- and Electroproduction

Carlo Ewerz·Otto Nachtmann
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Abstract

We show that diffractive production of a single neutral pion in photon-induced reactions at high energy is dynamically suppressed due to the approximate chiral symmetry of QCD. These reactions have been proposed as a test of the odderon exchange mechanism. We show that the odderon contribution to the amplitude for such reactions vanishes exactly in the chiral limit. This result is obtained in a nonperturbative framework and by using PCAC relations between the amplitudes for neutral pion and axial vector current production.

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Carlo Ewerz, Otto Nachtmann. 2006-08-07. Chiral Symmetry and Diffractive Neutral Pion Photo- and Electroproduction. https://doi.org/10.1140/epjc%2Fs10052-006-0082-9

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