Get started
Work

Resolution of the Pion-Photon Transition Form Factor Anomaly: Substrate Dynamic Shear Hardening, Asymptotic Over-Shooting of the Brodsky-Lepage Limit, and the Elimination of Endpoint Singularities in BaBar Data

Year: 2026
Type: preprint
Abstract: In perturbative QCD, collinear factorization dictates that the pion-photon transition form factor F_πγ(Q^2) must plateau monotonically toward the Brodsky-Lepage asymptotic limit: Q^2 F_πγ(Q^2) -> √2 f_π ≈ 0.185 GeV as Q^2 -> ∞. However, measurements by the BaBar collaboration at SLAC (Q^2 = 4–40 GeV^2) established an acute anomaly: above Q^2 ≈ 10 GeV^2, the scaled form factor continuously rises, reaching ~0.28 GeV at 35–40 GeV^2 and exceeding the asymptotic ceiling by over 50% (>4σ). Reconciling this within standard QCD requires unphysical, endpoint-singular Chernyak-Zhitnitsky distribution amplitudes that conflict with lattice QCD and charged pion form factors. Building upon our foundational series on the physical vacuum as an elastically pre-stressed continuum, we show that this high-Q^2 growth is the deterministic consequence of non-linear substrate shear hardening during extreme momentum transfers. In our ontology, photons are transverse acoustic shear wavepackets and the neutral pion is a non-topological breathing strain soliton. At extreme virtualities (Q^2 ≫ 10 GeV^2), the concentrated acoustic strain rate drives the pre-stressed continuum into non-linear elastic response, locally stiffening the effective shear modulus G_v^eff(Q^2) = G_v [1 + ξ_sub ln(1 + Q^2 / M_0^2)]. We derive the modified asymptotic scaling Q^2 F_πγ(Q^2) = √2 f_π [1 + (α_s / 2π) ξ_sub ln(1 + Q^2 / M_0^2)], reproducing the BaBar high-Q^2 ascent and the Belle intermediate-range plateau under Occam's razor without exotic distribution amplitudes or broken factorization.
DOI: 10.5281/zenodo.24144697
Language: English
Open Access status: green
OpenAlex ID: W7225834263
Cites:
Cited by:
Related to: