# ============================================================================ # P04 — B-L Z' production cross section vs $g_1'$ at fixed kinetic mixing # ---------------------------------------------------------------------------- # Adapts ColliderAgent paper-reproduction prompt: # /home/shiqiu/ColliderAgent/paper-reproduction/1605.02910/prompt_figure_10.md # Source: arXiv:1605.02910 — same kinetic-mixing B-L Z' model as P03 but # different diagnostic figure: $\sigma(pp \to Z')$ vs $g_1'$ for fixed # $\tilde g$ slices at $\sqrt{s}=13$ TeV. # ============================================================================ id: P04 title: "Reproducing $\\sigma(pp \\to Z')$ vs $g_1'$ slices for kinetic-mixing B-L Z' at $\\sqrt{s}=13$ TeV" arxiv_id: "1605.02910" venue: "ARC-Bench Physics 2026" paper_asset: null synthesis: | Reproducing the $\sqrt{s}=13$ TeV LHC production cross section $\sigma(pp \to Z')$ as a function of $g_1'$ along three constant- $\tilde g$ slices, for the same kinetic-mixing B-L $Z'$ model as P03. The cross section is exactly quadratic in the couplings, $\sigma(g_1', \tilde g) = A g_1'^2 + B g_1' \tilde g + C \tilde g^2$, so 3 MadGraph runs per mass point determine $(A,B,C)$ on the entire $(g_1', \tilde g)$ plane. The diagnostic figure has two panels (Panel A: $M_{Z'}=2$ TeV with $\tilde g\in\{0, -0.05, -0.10\}$; Panel B: $M_{Z'}=3$ TeV with $\tilde g\in\{0, -0.30, -0.60\}$). A credible study (a) reuses the kinetic-mixing B-L $Z'$ model (FeynRules + UFO), (b) executes 6 MadGraph runs (3 per mass) at $\sqrt{s}=13$ TeV, (c) solves the linear system for $(A,B,C)$ at each mass, (d) computes the analytic curves $\sigma(g_1')|_{\tilde g}$ for the requested slices, and (e) plots two panels with log-y on the prescribed ranges (Panel A: $g_1' \in [0, 0.20]$, $\sigma \in [10^{-4}, 10^{-1}]$ pb; Panel B: $g_1' \in [0, 0.70]$, $\sigma \in [10^{-4}, 10^{1}]$ pb). Research question: *does the agent recover the quadratic-in-couplings parameterization of $Z'$ production well enough to reproduce the constant-$\tilde g$ cross-section slices in Figure 10 of arXiv:1605.02910?* hypotheses: - id: H1 statement: "At Panel A ($M_{Z'}=2$ TeV, $\\tilde g = 0$, $g_1' = 0.10$), the reconstructed $\\sigma(pp \\to Z')$ lies within $\\pm 30\\%$ of the published value." measurable: true - id: H2 statement: "The curve at $\\tilde g = -0.10$ in Panel A lies above the $\\tilde g = 0$ curve at $g_1' = 0.05$ but below at $g_1' = 0.20$, demonstrating the destructive-then-constructive interference pattern of the kinetic mixing." measurable: true - id: H3 statement: "$\\sigma$ at ($M_{Z'}=2$ TeV, $g_1'=0.10$, $\\tilde g=0$) exceeds $\\sigma$ at ($M_{Z'}=3$ TeV, $g_1'=0.10$, $\\tilde g=0$) by a factor in $[10, 200]$, reflecting the steep PDF suppression." measurable: true experiment_design: research_question: "Does the agent reproduce $\\sigma(pp \\to Z')$ vs $g_1'$ for fixed-$\\tilde g$ slices at $M_{Z'}=2$ and 3 TeV at $\\sqrt{s}=13$ TeV (Figure 10 of arXiv:1605.02910)?" conditions: - name: "mzp_2tev_3runs" description: "$M_{Z'}=2$ TeV at $\\sqrt{s}=13$ TeV: 3 signal runs at $(g_1', \\tilde g) \\in \\{(0.10, 0), (0.10, -0.10), (0.15, -0.05)\\}$." - name: "mzp_3tev_3runs" description: "$M_{Z'}=3$ TeV at $\\sqrt{s}=13$ TeV: 3 signal runs at $(g_1', \\tilde g) \\in \\{(0.30, 0), (0.30, -0.30), (0.50, -0.60)\\}$." baselines: - "Self-consistency cross-check: predicted $\\sigma$ at the 3 input points must reproduce the simulated $\\sigma$ exactly (closure of the $A,B,C$ fit)" metrics: - name: "cross_section_pb" direction: "match_reference" description: "$\\sigma(pp \\to Z')$ in pb on the requested slice points." - name: "quadratic_coefficients_ABC_13tev" direction: "match_reference" description: "$(A, B, C)$ coefficients per mass point at $\\sqrt{s}=13$ TeV." - name: "mass_pdf_suppression_ratio" direction: "match_reference" description: "$\\sigma(M_{Z'}=2)/\\sigma(M_{Z'}=3)$ at $\\tilde g = 0$, $g_1' = 0.10$." datasets: - process_id: "pp_to_Zprime_BL_kinmix_13tev" sqrt_s_TeV: 13 description: "$pp \\to Z'$ for the kinetic-mixing B-L Z' model at LHC Run 2 energy." compute_requirements: gpu_required: false estimated_wall_clock_sec: 3600 rubric_path: "experiments/arc_bench/config/physics/rubrics/P04.json" # --------------------------------------------------------------------------- # Agent-mode requirements (consumed by researchclaw.pipeline.requirements_judge # at stage 15 RESEARCH_DECISION). Schema mirrors B01.yaml: # id — stable identifier # type — advisory hint to the LLM judge (numeric | artifact | discussion) # description — natural-language statement of what must be true post-run # must_pass — true → unmet ⇒ rerun (1 retry max); false → optional # # The five generic must_pass items apply uniformly across P01-P10; the sixth # is topic-specific (mirrors this manifest's H1). The two must_pass=false # items reward mechanistic interpretation and MC-reproducibility metadata # without blocking proceed-vs-rerun on them. # --------------------------------------------------------------------------- requirements: - id: req_results_json type: artifact description: >- A canonical results.json file exists at the workspace root with at least the keys: primary_metric (number), metric_key (string), metrics (object with numeric keys), hypotheses (object with h1/h2/h3 entries each carrying a `supported` boolean), summary (non-empty string). must_pass: true - id: req_metrics_numeric type: numeric description: >- results.json metrics MUST contain at least 3 numeric (non-null, finite) values directly relevant to the headline physics observable named in the experiment_design.metrics list above — these are the numbers the paper will report in its Results section. must_pass: true - id: req_hypotheses_supported_flags type: discussion description: >- results.json hypotheses.h1/h2/h3 each MUST have an explicit `supported` boolean AND a `details` string ≥ 40 characters quoting the numerical evidence (specific values + their source artifact) used to reach the verdict. must_pass: true - id: req_publication_figure type: artifact description: >- At least one publication-quality figure file (PDF or PNG, ≥150 DPI for raster) exists under figures/ or output/figures/ with axes labeled in physical units (GeV / pb / fb / dimensionless) and a legend if multiple series are plotted. The figure must directly support a hypothesis verdict. must_pass: true - id: req_model_implementation type: artifact description: >- The BSM Lagrangian is implemented either as a FeynRules .fr file (models/*.fr) with a matching UFO directory (models/*_UFO/ containing at least particles.py, parameters.py, couplings.py, vertices.py), OR as analytic Python code that explicitly computes the cross sections from the Lagrangian terms. A pure SM baseline with no BSM piece is NOT sufficient. must_pass: true - id: req_xsec_Zprime_2TeV type: numeric description: >- results.json metrics MUST report `sigma_pp_to_Zprime_2TeV_panelA_fb` (at M_Z'=2 TeV, g̃=0, g1'=0.10) within ±30% of the published Panel A reference cross section. must_pass: true - id: req_mechanistic_writeup type: discussion description: >- The summary or structured_results section provides a one-paragraph mechanistic interpretation of WHY the headline observable comes out the way it does (which interference / propagator structure / cut effect drives the result). Nice-to-have, not blocking proceed. must_pass: false - id: req_mc_reproducibility type: discussion description: >- results.json or a sibling reproducibility section names: (a) the MadGraph5_aMC@NLO version, (b) the PDF set used (if applicable), (c) at least one explicit random seed. Required for full reproducibility but not for scientific correctness. must_pass: false