Machine: e⁻ 5–18 GeV on p 41–275 GeV or Au up to 110 GeV/u; 25 mrad crossing angle, hadrons → +z (forward), electrons → −z (backward). EIC CDR, BNL-221006-2021-FORE (2021); BNL EIC machine page.
DIS kinematics: Q² = −q², x = Q²/2P·q, y = P·q/P·k, W² = (P+q)². Events drawn from d²σ/dx dQ² ∝ [1+(1−y)²] F₂/(xQ⁴) (FL, γZ neglected), toy F₂ ∝ x−λ, λ = 0.048 ln(Q²/Λ²) (cf. H1, PLB 520, 183, 2001). Cuts 0.01 < y < 0.95, W² > 10 GeV².
Hadronisation: longitudinal phase space in the γ*p centre-of-mass frame (leading baryon + rapidity plateau, ⟨pT⟩ ≈ 0.35 GeV, ⟨n⟩ ∝ ln W²), exact 4-momentum conservation; not a Lund string (cf. PYTHIA 8.3, SciPost Phys. Codebases 8, 2022). π⁰, η → γγ.
e+Au: incoherent DIS on one nucleon (no nuclear PDFs), plus evaporation neutrons → ZDC (zero-degree calorimeter) and protons → OMD (off-momentum detectors).
Granularity: EEEMCal 2 cm crystals; BIC drawn Δφ×Δη ≈ 0.049×0.05, FEMC 5 cm (real ≈ 2.5 cm), HCals 10 cm or Δη = Δφ ≈ 0.1. Tower height ∝ ln(1 + E/50 MeV).
Far forward: B0 (z ≈ 6 m), OMD (≈ 22.5 m), Roman pots (≈ 26–28 m), ZDC (≈ 35.8 m). Drawn as straight lines (dipole bending not simulated), path compressed ×0.15 beyond z = 4.5 m. Kinematics generated head-on; hadronic final state rotated by the crossing angle (approximation).
Scale: hadrons drawn at true size by default; the Hadron zoom slider magnifies the proton (R ≈ 0.84 fm) or Au (R ≈ 6.4 fm), the γ* exchange and the colour string. Lorentz contraction drawn at γ = 12.