The Odderon in Quantum Chromodynamics
Carlo Ewerz
TL;DR
The Odderon addresses high-energy QCD exchange with negative C-parity and is rooted in Regge theory, now treated in perturbative BKP and nonperturbative approaches. The perturbative Odderon comprises three reggeized gluons whose dynamics are exactly solvable in certain limits and reveal an underlying integrable structure tied to SL(2,C) symmetry; notable solutions (JW and BLV) yield intercepts near or at unity, with BLV explicitly at α_O = 1 and JW close to 0.96 for typical α_s. Unitarity in the perturbative regime is addressed via the generalized LLLA (GLLA) framework, including N-reggeon states and Pomeron–Odderon–Odderon vertices, while nonperturbative QCD provides complementary pictures through Regge phenomenology, nonperturbative propagators, and stochastic vacuum models. Phenomenologically, Odderon effects are explored in pp/p̄p elastic scattering, exclusive diffractive meson production in ep and γγ processes, and interference-based observables; although data are currently inconclusive, several channels (e.g., diffractive J/ψ at HERA, double-diffractive meson production, and photon-photon processes at future colliders) hold promise for unambiguous Odderon discovery and spectral characterization.
Abstract
The Odderon is the leading exchange in hadronic scattering processes at high energies in which negative charge conjugation and parity quantum numbers are transferred in the t-channel. We review the origin of the Odderon in Regge theory, its status in perturbative and nonperturbative Quantum Chromodynamics, as well as its phenomenology.
