# UTFANSWF NP-QCD Electromagnetic Prediction Contract — FROZEN
Date: 2026-08-19 America/New_York
Status: frozen before external correlator/target lookup

## Objective
Generate numerical outputs for the two new UTFANSWF electromagnetic-response channels without fitting or selecting against electromagnetic holdouts:

1. hadronic vacuum polarization response, ultimately Delta alpha_had^(5)(M_Z^2);
2. proton/neutron O(alpha) electromagnetic mass response, K_p^EM and K_n^EM, ultimately delta M_p^QED and delta M_n^QED.

## Frozen source object
Use one renormalized QCD electromagnetic current

J_mu^R = sum_f Q_f qbar_f gamma_mu q_f

with fixed rational quark charges and a unit-normalized external source B_mu. The nonperturbative response is evaluated at e=0. The electromagnetic normalization is applied only after the QCD response has been frozen.

## Vacuum projection
Pi_mu_nu^R(x,y) = d^2[-ln Z]/dB_mu(x)dB_nu(y) at B=0.
The numerical HVP estimator must include connected + disconnected contractions, declared current renormalization/conserved-current treatment, continuum control, finite/infinite-volume control, and declared pQCD matching for the high-energy tail.

## Nucleon projection
K_N^EM = dE_N/d(e^2) at e=0, equivalently the vacuum-subtracted nucleon expectation of the renormalized two-current photon-kernel insertion divided by Euclidean time at large t.
The estimator must use the same renormalized current and declared quark-mass renormalization/matching convention as the vacuum projection.

## Fixed QCD physical-point layer from v23
- alpha_s(M_Z) = 0.1184
- Lambda_MSbar^(3) = 339.7960719428473 MeV
- RGI M_ud = 4.7 MeV
- RGI M_s = 127.0 MeV
- isoQCD nucleon mass forward result = 941.2231331333769 +/- 35.184029612232145 MeV
These define/anchor the existing v23 QCD coordinate layer; they do not provide the missing electromagnetic current-current correlators.

## Anti-target rules
- Do not use measured alpha(0) or inverse-137 to choose any HVP model, kernel, tail, renormalization, or stopping rule.
- Do not use the physical proton or neutron mass to choose K_N^EM, counterterms, kernel, or stopping rule.
- Do not tune to a published HVP central value or published nucleon QED self-energy.
- Do not infer nucleon response algebraically from vacuum HVP.
- Do not use HB/NZ as a proton-radius fit law.
- Do not promote phenomenological VMD/DSE/model-kernel estimates as first-principles NP-QCD predictions.

## Numerical promotion classes
A. UTFANSWF_INTERNAL_PREDICTION: numerical current-current estimator is executed from source-complete QCD data under this frozen contract.
B. CONDITIONAL_EXTERNAL_NPQCD: a pre-existing independent NP-QCD matrix element is inserted after freeze; downstream number is a conditional UTFANSWF transport result, not an internally generated NP-QCD prediction.
C. DIAGNOSTIC_ONLY: any phenomenological/model reduction or target-exposed reconstruction.

## Required outputs
- Delta_alpha_had_5_MZ2
- K_p_EM
- K_n_EM
- deltaM_p_QED
- deltaM_n_QED
- Delta_plus_QED = 0.5*(deltaM_p_QED + deltaM_n_QED)
- downstream alpha_inverse_0 from the frozen upstream electromagnetic normalization + HVP transport
- full physical proton prediction after the frozen isovector/quark-mass layer and EM response are combined, if all required pieces are available without target tuning.

## Promotion rule
No result is called a new UTFANSWF numerical prediction unless it satisfies class A. Class B is explicitly labeled conditional. Class C cannot be promoted.
