{ "vercy": "1.0-draft", "publication": { "status": "research-draft", "adjudicationStatus": "unreviewed", "publishableCanonical": false, "generatedAt": "2026-09-06T20:29:50Z", "providers": [ "Codex", "Grok" ], "missingProviders": [], "pass": 2, "cost": { "grok": { "usd": 0.01218866, "turns": 1, "seconds": 157.6, "error": null }, "codex_seconds": 63.7 }, "enrichment": { "pass": 3, "engine": "claude", "producedAt": "2026-10-06T11:00:00Z", "ingestedAt": "2026-10-06T08:01:17+00:00", "fields": [ "agent_conduct", "ethics", "owners" ] }, "gate": { "passed": true, "version": "1.0", "at": "2026-10-07T10:10:28+00:00", "evidence": [ "completeness 1.00", "sense: Wikidata description", "4 live sources", "review by codex: pass" ] } }, "metaModel": { "id": "THING-Q2348", "registryId": "vr.tr.neutron", "name": "neutron", "version": "0.1.0-research.1", "entryKind": "thing", "family": "Thing Registry", "domain": [ "PHY.OBJ" ], "status": "research-draft" }, "canonicalUrl": "https://ver.cy/models/thing/q2348/", "model": { "registry_id": "vr.tr.neutron", "name": "neutron", "purpose": "Enable an AI agent to recognise a neutron, assess its physical context and evidence, and identify applicable interactions, measurements and handling constraints.", "definition": "The neutron is an electrically neutral spin-½ baryon with quark content udd that, bound to protons by the residual strong force, makes up atomic nuclei; the free neutron is unstable and β⁻-decays to a proton, electron and electron antineutrino with a mean lifetime of about 879 s.", "scope_statement": "This model owns the identity, free or nuclear-bound context, motion, spin, possible interactions and observational evidence of a neutron; it relates the neutron to nuclei, fields, materials and instruments without owning their models.", "in_scope": [ "Neutron identity and discrimination from other neutral particles", "Free versus nuclear-bound context and associated state descriptions", "Energy, momentum and spin with reference frames and uncertainty", "Context-dependent scattering, capture, production and decay possibilities", "Evidence supporting neutron attribution and limits on individual tracking" ], "out_of_scope": [ "Whole-nucleus composition, structure and stability", "Atomic electronic structure and chemical bonding", "Collective neutron matter and neutron-star structure", "Beam, source and reactor operation", "Detector design, calibration procedures and facility radiation protection" ], "distinguishing_features": [ "A neutron has zero net electric charge; a proton has positive elementary charge. Charge neutrality alone does not establish neutron identity.", "A neutron is a massive spin-one-half baryon with strong nuclear interactions; a neutrino is a lepton and does not exhibit that interaction signature.", "A neutron is a massive spin-one-half particle; a photon is a massless spin-one particle.", "A neutron is a nucleon without an atomic electron structure; a neutral atom contains a nucleus and electrons.", "A neutron has baryon number +1; an antineutron has baryon number -1. Their equal charge and similar mass do not distinguish them." ], "characteristics": [ { "name": "Identity attribution", "kind": "category", "unit_or_values": "neutron candidate | neutron attribution supported | unresolved neutral-particle attribution", "why_it_matters": "Separates the proposed particle identity from the strength of the evidence." }, { "name": "Physical context", "kind": "state", "unit_or_values": "free | nuclear-bound | unresolved", "why_it_matters": "Determines which motion, lifetime and interaction descriptions are applicable." }, { "name": "Host nucleus", "kind": "relation", "unit_or_values": "Reference to a nucleus and its state, where nuclear-bound", "why_it_matters": "Locates binding and stability claims in the nuclear system that determines them." }, { "name": "Kinetic energy", "kind": "measurement", "unit_or_values": "eV with reference frame and uncertainty; applicability stated", "why_it_matters": "Helps determine interaction probabilities and measurement methods for a free neutron." }, { "name": "Momentum", "kind": "measurement", "unit_or_values": "kg·m/s or MeV/c with coordinates, reference frame and uncertainty", "why_it_matters": "Supports transport and reaction reasoning without assuming a uniquely known trajectory." }, { "name": "Spin description", "kind": "state", "unit_or_values": "Specified spin state, ensemble polarisation, or unknown; reference axis required", "why_it_matters": "Supports magnetic and spin-dependent interaction reasoning while distinguishing individual and ensemble claims." }, { "name": "Interaction environment", "kind": "relation", "unit_or_values": "References to target isotopes, material conditions and applied fields", "why_it_matters": "Neutron interaction possibilities depend on the surrounding physical system." }, { "name": "Event outcome", "kind": "state", "unit_or_values": "scattered | captured | decayed | other reaction | outcome unresolved", "why_it_matters": "Prevents an agent from assuming the neutron persists after an event that consumes or transforms it." }, { "name": "Observation basis", "kind": "relation", "unit_or_values": "References to detector events, preparation records and inference methods", "why_it_matters": "Makes attribution, uncertainty and alternative explanations inspectable." } ], "affordances": [ "Assess whether observations support neutron identity over competing particle explanations.", "Select a free-particle or nuclear-system description appropriate to the context.", "Estimate transport and interaction outcomes using applicable material and nuclear data.", "Identify measurements that could constrain energy, direction or spin.", "Evaluate candidate moderation, scattering, capture or spin-manipulation actions through linked apparatus models.", "Record loss, transformation or unresolved continuation after an interaction." ], "agent_conduct": { "may": [ "Explain neutron properties and physics from established sources.", "Read and report neutron monitor and dosimeter data where the agent is authorized." ], "must_not": [ "Assist in producing or using neutron sources or fissile materials to harm people.", "Bypass shielding, interlocks or dose limits at facilities that produce neutrons.", "Present uncertain neutron measurements as settled values.", "Leave people exposed to neutron radiation beyond lawful limits." ], "requires_human": [ "Any work with neutron sources or reactors that affects people's exposure." ] }, "ethics": { "considerations": [ "Neutron radiation can injure tissue and activate materials.", "Neutron physics underlies both energy and weapons, so lawful use matters." ], "affected_parties": [ "Radiation workers", "The public near facilities", "Researchers" ] }, "owners": { "steward": "Nobody owns the particle; nuclear regulators license sources and facilities that produce neutrons.", "master_systems": [ "Radioactive source registers" ] }, "what_it_is_for": [ "Neutrons occur as constituents of most atomic nuclei and as free particles in certain nuclear reactions.", "Neutron beams are used to investigate material structure, image objects and study nuclear properties.", "Their interactions also matter in nuclear energy systems, radiation protection and isotope production." ], "standards_and_regulation": [ "General Safety Requirements Part 3, issued by the International Atomic Energy Agency and joint sponsoring organizations, establishes international safety requirements for protection against ionizing radiation, including neutron exposure." ], "failure_modes_and_hazards": [ "Neutron radiation can damage living tissue through interactions that produce secondary charged particles.", "Neutron irradiation can activate materials and create subsequent radiation hazards.", "Neutron exposure can degrade structural materials and disrupt electronic systems.", "Unsuitable monitoring or shielding assumptions can underestimate neutron radiation exposure." ], "facets_not_applicable": { "recognition": "An individual neutron has no visually observable identifying features and requires instrumental evidence for identification." } }, "sources": [ { "id": "pdg-rpp", "title": "Review of Particle Physics (neutron listings: mass, lifetime, magnetic moment, quantum numbers)", "url": "https://pdg.lbl.gov", "what_it_supports": "Particle identity, PDG Monte Carlo number 2112, rest energy, mean lifetime and the beam-versus-bottle lifetime tension, magnetic moment, and decay mode.", "url_status": "live" }, { "id": "codata-nist", "title": "CODATA recommended values of the fundamental physical constants (neutron mass and related constants)", "url": "https://physics.nist.gov/cuu/Constants/", "what_it_supports": "CODATA neutron rest mass, molar mass, Compton wavelength, and magnetic-moment values used for metrology.", "url_status": "live" }, { "id": "iso-80000-10", "title": "ISO 80000-10, Quantities and units - Part 10: Atomic and nuclear physics", "url": "", "what_it_supports": "Standard names and symbols for nucleon, neutron, fluence, fluence rate, and related nuclear quantities." }, { "id": "icrp-103", "title": "ICRP Publication 103, The 2007 Recommendations of the International Commission on Radiological Protection", "url": "", "what_it_supports": "Energy-dependent radiation weighting factors w_R for neutrons in occupational and public dose assessment." }, { "id": "wikidata", "title": "Wikidata item Q2348: neutron", "url": "https://www.wikidata.org/wiki/Q2348", "url_status": "live", "what_it_supports": "identity and sense of the item", "checked_by": "wikidata-api" }, { "id": "wikipedia-en", "title": "Wikipedia: Neutron", "url": "https://en.wikipedia.org/wiki/Neutron", "url_status": "live", "what_it_supports": "general description of the item", "checked_by": "wikidata-api sitelink" } ], "structure": { "bundles": [ { "id": "neutron-identity", "name": "Neutron identity", "description": "Criteria for identifying a neutron without treating every neutral signal as one.", "rationale": "An agent needs both defining particle properties and an explicit basis for attributing those properties to an observation.", "layers": [ { "id": "particle-definition", "name": "Particle definition", "description": "The properties that distinguish a neutron from neighbouring particle kinds.", "findings": [ { "id": "neutral-nucleon-criteria", "name": "Neutral nucleon criteria", "description": "Require an identity account consistent with a neutral spin-one-half baryon rather than neutrality alone.", "questions": [ { "text": "Which particle properties define the neutron in the adopted physical description?", "kind": "definition", "id": "neutral-nucleon-criteria-q01" }, { "text": "Which evidence distinguishes this attribution from a proton, neutrino, photon, neutral atom or antineutron?", "kind": "boundary", "id": "neutral-nucleon-criteria-q02" } ] } ] }, { "id": "identity-evidence", "name": "Identity evidence", "description": "The preparation and observation records supporting neutron attribution.", "findings": [ { "id": "attribution-support", "name": "Attribution support", "description": "Connect the neutron claim to production context and observed signatures while retaining alternatives.", "questions": [ { "text": "What source process or preparation record supports the presence of a neutron?", "kind": "provenance", "id": "attribution-support-q01" }, { "text": "What background or competing particle explanation remains compatible with the observed signal?", "kind": "measurement", "id": "attribution-support-q02" } ] } ] } ] }, { "id": "free-and-bound-context", "name": "Free and bound context", "description": "Whether the neutron is free or belongs to a nuclear system, and what that permits an agent to assert.", "rationale": "Free-neutron behaviour cannot be transferred directly to a neutron bound in a nucleus.", "layers": [ { "id": "binding-context", "name": "Binding context", "description": "The host system and limits of an individual-neutron description.", "findings": [ { "id": "nuclear-membership", "name": "Nuclear membership", "description": "Identify the host nucleus where applicable and avoid assigning unsupported classical individuality to a bound neutron.", "questions": [ { "text": "Is the neutron free, bound in an identified nuclear state, or unresolved between these descriptions?", "kind": "boundary", "id": "nuclear-membership-q01" }, { "text": "Which properties can be attributed to this neutron individually, and which belong to the nuclear state?", "kind": "boundary", "id": "nuclear-membership-q02" } ] } ] }, { "id": "persistence-and-transformation", "name": "Persistence and transformation", "description": "How free decay and nuclear transitions affect neutron persistence.", "findings": [ { "id": "contextual-stability", "name": "Contextual stability", "description": "Separate free-neutron beta decay from transitions whose availability is determined by a host nucleus.", "questions": [ { "text": "Which decay or nuclear-transition description applies in this context, and what evidence supports it?", "kind": "definition", "id": "contextual-stability-q01" }, { "text": "What observation would establish that the neutron has transformed rather than merely left the observed region?", "kind": "measurement", "id": "contextual-stability-q02" } ] } ] } ] }, { "id": "motion-and-spin", "name": "Motion and spin", "description": "The neutron's translational and spin state at the resolution justified by preparation or measurement.", "rationale": "Energy and spin influence neutron interactions and determine which manipulations are physically applicable.", "layers": [ { "id": "neutron-kinematics", "name": "Neutron kinematics", "description": "Energy, momentum and spatial evidence with their reference frames.", "findings": [ { "id": "energy-and-direction", "name": "Energy and direction", "description": "Record measured or inferred motion without substituting a beam average for an individual neutron value.", "questions": [ { "text": "What energy and direction are supported, in which frame, and with what uncertainty?", "kind": "measurement", "id": "energy-and-direction-q01" }, { "text": "Does the evidence constrain this neutron, a selected event population, or the source spectrum?", "kind": "boundary", "id": "energy-and-direction-q02" } ] } ] }, { "id": "spin-and-magnetic-response", "name": "Spin and magnetic response", "description": "Spin preparation, measurement and coupling to magnetic fields.", "findings": [ { "id": "spin-state-support", "name": "Spin state support", "description": "Represent neutron spin relative to specified axes and distinguish it from ensemble polarisation.", "questions": [ { "text": "What spin state or polarisation is established, relative to which axis and preparation method?", "kind": "measurement", "id": "spin-state-support-q01" }, { "text": "Which field arrangement could manipulate or analyse the spin under the stated conditions?", "kind": "action", "id": "spin-state-support-q02" } ] } ] } ] }, { "id": "neutron-interactions", "name": "Neutron interactions", "description": "Scattering and neutron-consuming reactions in an identified environment.", "rationale": "Useful action choices require energy-dependent and target-dependent interaction evidence.", "layers": [ { "id": "scattering-and-moderation", "name": "Scattering and moderation", "description": "Changes in neutron energy and direction through interactions with matter.", "findings": [ { "id": "scattering-outcomes", "name": "Scattering outcomes", "description": "Relate possible energy and direction changes to target composition, conditions and applicable scattering data.", "questions": [ { "text": "Which scattering data apply to the neutron energy, target isotopes and material conditions?", "kind": "provenance", "id": "scattering-outcomes-q01" }, { "text": "Would the proposed material arrangement produce the intended energy or direction change, with what uncertainty?", "kind": "action", "id": "scattering-outcomes-q02" } ] } ] }, { "id": "capture-and-reactions", "name": "Capture and reactions", "description": "Processes that absorb the neutron or produce a changed set of particles.", "findings": [ { "id": "reaction-consequences", "name": "Reaction consequences", "description": "Identify applicable reaction channels and their products without assuming continuity of the incoming neutron.", "questions": [ { "text": "Which capture or other reaction channels are supported for this target and neutron energy?", "kind": "definition", "id": "reaction-consequences-q01" }, { "text": "Which reaction products, activation effects or secondary emissions must a proposed action account for?", "kind": "action", "id": "reaction-consequences-q02" } ] } ] } ] }, { "id": "detection-and-inference", "name": "Detection and inference", "description": "How neutron interactions become observable events and how those events constrain neutron claims.", "rationale": "Neutron observations commonly rely on interaction products, so event interpretation is central to recognising and tracking the thing.", "layers": [ { "id": "detection-signatures", "name": "Detection signatures", "description": "The link from a neutron interaction to a recorded instrument signal.", "findings": [ { "id": "signal-to-neutron-link", "name": "Signal-to-neutron link", "description": "Require a supported account of the conversion reaction or recoil process behind an attributed neutron event.", "questions": [ { "text": "Which interaction converts neutron presence into the recorded signal?", "kind": "definition", "id": "signal-to-neutron-link-q01" }, { "text": "What detector response, efficiency and background evidence supports the interpretation at this neutron energy?", "kind": "provenance", "id": "signal-to-neutron-link-q02" } ] } ] }, { "id": "measurement-limits", "name": "Measurement limits", "description": "Limits imposed by resolution, missed events and measurement-induced interactions.", "findings": [ { "id": "event-continuity", "name": "Event continuity", "description": "Separate detected events from inferred histories and record whether measurement leaves an outgoing neutron.", "questions": [ { "text": "Does the measurement absorb the neutron, scatter it, or leave its subsequent state unresolved?", "kind": "boundary", "id": "event-continuity-q01" }, { "text": "What timing, geometry and uncertainty justify associating multiple observations with one neutron history?", "kind": "measurement", "id": "event-continuity-q02" } ] } ] } ] }, { "id": "evidence-and-external-alignment", "name": "Evidence and external alignment", "description": "What the world already says about this thing, gathered so the model can be checked against it.", "rationale": "A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.", "layers": [ { "id": "reported-evidence", "name": "Reported evidence", "description": "Findings from the breadth pass, kept separate from the structural claims.", "findings": [ { "id": "evidence-kinds", "name": "Kinds and varieties", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "bound (intranuclear) neutrons", "free neutrons", "thermal neutrons", "epithermal neutrons", "fast neutrons", "cold and ultracold neutrons", "prompt and delayed fission neutrons", "antineutrons" ], "questions": [ { "id": "evidence-kinds-q01", "text": "Which of these kinds and varieties hold for the sense of neutron this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-identifiers", "name": "Identifiers and schemes", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ { "scheme": "Wikidata", "value_or_pattern": "Q2348", "note": "Item for the neutron as a particle." }, { "scheme": "PDG Monte Carlo particle numbering", "value_or_pattern": "2112", "note": "Antineutron is −2112; PDG name n." }, { "scheme": "IUPAC inorganic nomenclature", "value_or_pattern": "n or ¹n", "note": "Nucleon number 1, charge number 0; not a nuclide of an element." }, { "scheme": "CAS Registry Number", "value_or_pattern": "12586-31-1", "note": "Assigned to the free neutron in chemical registry practice; unused in particle physics." } ], "questions": [ { "id": "evidence-identifiers-q01", "text": "Which of these identifiers and schemes hold for the sense of neutron this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-standards-and-regulation", "name": "Standards and regulation", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "ISO 80000-10 (ISO) - quantities and units for atomic and nuclear physics, including neutron fluence and related symbols.", "ICRP Publication 103 (ICRP) - radiation weighting factors for neutrons as a function of energy, used to convert absorbed dose to equivalent dose.", "ICRU reports on neutron dosimetry and operational quantities (ICRU) - kerma, ambient dose equivalent H*(10), and personal dose equivalent for neutron fields.", "IAEA Safety Standards and Nuclear Data Services / ENDF-format libraries (IAEA and national data centres) - evaluated neutron cross sections, source categorisation, and transport data.", "National nuclear-safety rules for neutron-emitting sealed sources and criticality (e.g. US NRC 10 CFR Parts 20 and 70; equivalent IAEA GSR/SSR documents) - licensing of ²⁵²Cf, Am-Be and reactor/spallation sources." ], "questions": [ { "id": "evidence-standards-and-regulation-q01", "text": "Which of these standards and regulation hold for the sense of neutron this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-real-world-use", "name": "Real-world use", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "Fission-chain reactors and criticality control: neutrons induce fission, are moderated, absorbed, and leaked; delayed neutrons set reactor period.", "Neutron scattering and reflectometry at reactors and spallation sources (ILL, SNS, J-PARC, ISIS) to measure structure and dynamics of condensed matter.", "Neutron activation analysis and prompt-gamma analysis for elemental assay of samples, oil-well logging, and explosives/ contraband detection.", "Neutron radiography and tomography of hydrogenous or dense objects (aerospace, nuclear fuel, cultural heritage).", "Radiation oncology (boron neutron capture therapy; historically fast-neutron therapy) and calibration of area survey meters.", "Secondary cosmic-ray neutrons at aviation altitudes and sea level, used both as a radiation-protection field and as a probe of soil moisture via cosmic-ray neutron sensing." ], "questions": [ { "id": "evidence-real-world-use-q01", "text": "Which of these real-world use hold for the sense of neutron this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-measurements", "name": "Typical measurements", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ { "quantity": "rest energy (mass)", "typical_range": "939.5654205 (CODATA; uncertainty in last digits)", "unit": "MeV" }, { "quantity": "mean lifetime of the free neutron", "typical_range": "878-888 (method-dependent; bottle vs beam discrepancy)", "unit": "s" }, { "quantity": "magnetic moment", "typical_range": "−1.9130427", "unit": "nuclear magneton (μ_N)" }, { "quantity": "mean-square charge radius", "typical_range": "about −0.116", "unit": "fm²" }, { "quantity": "kinetic energy (thermal Maxwellian at ~293 K)", "typical_range": "0.025", "unit": "eV" }, { "quantity": "kinetic energy (fast fission / continuum)", "typical_range": "0.1-15 (fission spectrum peaks near 0.7-2)", "unit": "MeV" }, { "quantity": "thermal neutron flux in power-reactor cores", "typical_range": "1e12-1e15", "unit": "cm⁻² s⁻¹" }, { "quantity": "sea-level cosmic-ray neutron fluence rate (order of magnitude, energy-integrated)", "typical_range": "0.01", "unit": "cm⁻² s⁻¹" } ], "questions": [ { "id": "evidence-measurements-q01", "text": "Which of these typical measurements hold for the sense of neutron this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-failure-modes-and-hazards", "name": "Failure modes and hazards", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "Free-neutron β⁻ decay removes the particle on a ~15 min scale and produces a proton, electron and antineutrino; relevant to beamline backgrounds and ultracold-neutron losses.", "Biological damage with high relative biological effectiveness: thermal capture on ¹⁴N and ¹H, and dense ionization by recoil protons from fast neutrons.", "Activation of structures and impurities ((n,γ), (n,p), (n,α), (n,2n)), producing radioactive waste and shutdown dose rates.", "Displacement damage and helium/hydrogen transmutation: reactor-pressure-vessel embrittlement, fuel-cladding swelling, and semiconductor displacement/SEU from atmospheric neutrons.", "Inadvertent criticality when a multiplying assembly exceeds k_eff = 1, yielding an intense neutron and gamma pulse.", "Shielding failure: hydrogenous shields thermalize and capture; high-Z shields alone are poor for fast neutrons and can generate secondary neutrons via (γ,n) or spallation." ], "questions": [ { "id": "evidence-failure-modes-and-hazards-q01", "text": "Which of these failure modes and hazards hold for the sense of neutron this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-regional-variation", "name": "Regional variation", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ "Thermal/epithermal group boundaries are convention-dependent: a 0.5 eV cadmium cutoff is common; some reactor libraries use 0.625 eV or 1 eV, and condensed-matter work uses a Maxwellian at moderator temperature rather than a hard cutoff.", "Evaluated nuclear data libraries (ENDF/B in the US, JEFF in Europe, JENDL in Japan, CENDL in China, BROND in Russia) differ in neutron cross sections, covariances and thermal scattering laws (S(α,β)).", "Sealed-source categorisation and transport labelling follow IAEA but are implemented under national regulators (NRC, ONR, ASN, Rosatom, etc.) with different activity thresholds for ²⁵²Cf and (α,n) sources.", "The particle name is internationally stable (neutron / Neutron / нейтрон / 中性子); popular and military usage of 'neutron bomb' versus 'enhanced radiation weapon' varies by language and doctrine, not by physics." ], "questions": [ { "id": "evidence-regional-variation-q01", "text": "Which of these regional variation hold for the sense of neutron this model covers, and on what evidence?", "kind": "provenance" } ] }, { "id": "evidence-neighbours", "name": "Neighbouring kinds and how to tell them apart", "description": "Reported by the breadth pass; each item needs checking against its source before it becomes normative.", "evidence": [ { "name": "proton", "difference": "Same baryon family but charge +e, slightly lower mass, and stable as a free particle; separate by electromagnetic deflection, ionization, or (n,p) versus (p,n) kinematics." }, { "name": "neutrino (especially electron antineutrino from neutron decay)", "difference": "Lepton with no strong interaction; a neutrino beam is essentially unattenuated by metres of polyethylene that thermalize and absorb neutrons." }, { "name": "neutral pion", "difference": "Light spin-0 meson (≈135 MeV) that decays to two photons in ~10⁻¹⁶ s; a neutron is a long-lived baryon of ≈940 MeV that does not decay to photons." }, { "name": "hydrogen atom", "difference": "Electrically neutral but an electron-proton bound state of atomic size and 13.6 eV ionization energy; a neutron is a femtometre-scale baryon with no electron and no optical spectrum." }, { "name": "antineutron", "difference": "Baryon number −1; annihilates on contact with nucleons into pions. Same mass and lifetime as the neutron; separated by annihilation signatures or by production/tag in antiproton beams." }, { "name": "neutron-star matter ('neutronium')", "difference": "A many-body degenerate state at nuclear and supra-nuclear density, not a free or singly bound neutron; laboratory neutrons are single particles or nucleons inside ordinary nuclei." } ], "questions": [ { "id": "evidence-neighbours-q01", "text": "Which of these neighbouring kinds and how to tell them apart hold for the sense of neutron this model covers, and on what evidence?", "kind": "provenance" } ] } ] } ] } ] }, "openQuestions": [ "Which authoritative references and uncertainty conventions should govern neutron properties and free-neutron lifetime estimates?", "Which existing Vercy models own nuclei, particle ensembles, sources and detectors, and how should neutron records link to them?", "What minimum evidence should qualify an observation as a supported neutron attribution in different detector contexts?", "How should the model represent bound-neutron properties when individual identity or a classical trajectory is not physically justified?", "Which evaluated interaction datasets and energy-regime definitions should agents use for each intended application?" ], "statistics": { "bundles": 6, "layers": 11, "findings": 18, "questions": 28 } }