A microscopic stochastic field theory for nonlinear pomeron--odderon evolution based on a Doi--Peliti framework

Abstract

We construct a reaction-based microscopic realisation of nonlinear pomeron--odderon evolution in rapidity and impact-parameter space. Using the Doi--Peliti formalism, we derive the master equations, their operator representation, the exact hierarchy of factorial moments, and the coherent-state functional integral. The construction admits normalised complex configuration weights while retaining the algebraic conservation law of the gain--loss generator. Pomeron branching and merging yield the complex logistic equation \cite{Kohara:2026} under mean-field factorisation. Pomeron-catalysed odderon branching and ternary odderon fusion provide an odd sector whose evolution is driven by the pomeron background. Without transverse diffusion, the resulting equations admit an analytical solution in quadrature, allowing us to examine amplification, phase evolution, and nonlinear regulation. A specified matching between the first moments and the even and odd scattering profiles connects this evolution to elastic-scattering observables. Illustrative initial conditions produce a nonmonotonic forward ratio and a splitting between the $pp$ and $p\bar p$ channels, while the interference near a diffractive minimum remains sensitive to the relative phases and transverse profiles. These examples illustrate the effective dynamics without constituting a fit to data or a general proof of scattering unitarity.