Chiral Inflation of the Pion Radius

TL;DR

This paper derives a non-perturbative expression for the pion's partonic structure at large transverse distances, revealing a novel 'chiral inflation' phenomenon where the pion radius exponentially grows with rapidity in a specific Bjorken x range.

Contribution

It introduces the concept of chiral inflation, showing how the pion radius expands exponentially with rapidity in a wide x region, linking partonic structure to chiral dynamics.

Findings

Derived asymptotic expression for q(x,b_perp) depending on F_pi and m_pi

Identified the phenomenon of chiral inflation with exponential radius growth

Connected partonic contributions to the logarithmic divergence of the pion radius

Abstract

We derive expression for the large b_perp asymptotic of the 3D parton distributions q(x,b_perp) in the pion. The asymptotic depends exclusively on the mass scales F_pi and m_pi. Therefore it provides us with a nice example of a strict non-perturbative result for the partonic structure of Nambu-Goldstone bosons in QCD. Analyzing the x-dependent pion transverse radius we reveal a new phenomenon of "chiral inflation"-- in the parametrically wide region of Bjorken x (m_pi^2/(4 pi F_pi)^2 << x << 1) the pion radius grows exponentially fast with the rapidity eta=ln(1/x). We show that the partons in this interval of Bjorken x contribute to famous logarithmic divergency of the pion radius. In other words, the partonic picture of the classical result of ChPT is provided. The phenomenon of the chiral inflation is at variance with the Gribov diffusion, because of long-range interaction of the Nambu-Goldstone bosons.