Chiral Symmetry and Diffractive Neutral Pion Photo- and Electroproduction

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.

22 pages, 7 figures

References in corpus (5)

• Big Bang Nucleosynthesis (in "The Review of Particle Properties" 2004)
• The Odderon in Quantum Chromodynamics
• Towards a Nonperturbative Foundation of the Dipole Picture: II. High Energy Limit
• The C-Odd Four-Gluon State in the Color Glass Condensate
• The Missing Odderon

Cited by in corpus (4)

• Exclusive J/psi and Upsilon hadroproduction and the QCD odderon
• Photoproduction of pi+ pi- pairs in a model with tensor-pomeron and vector-odderon exchange
• Exclusive $pp\to pp{\pi }^0$ reaction at high energies
• Searching for the odderon in $pp\to pp{K}^{+}{K}^{-}$ and $pp\to pp{\mu }^{+}{\mu }^{-}$ reactions in the $\varphi (1020)$ resonance region at the LHC