{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.massive-particle","code":"thing-q2923525","url":"https://ver.cy/models/thing/q2923525/","name":"massive particle","alternateNames":[],"kind":"thing","status":"published","version":"0.1.0-research.1","language":"en","classifiers":{"family":"Thing Registry","category":"Physical world and living systems","entryKind":"thing","plane":"PHY","domain":["PHY.OBJ"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"A massive particle is a particle with strictly positive invariant mass, whether elementary or composite, whose free motion in special relativity is timelike and slower than light in vacuum.","purpose":"Enable an AI agent to identify a massive particle, interpret its mass and motion, assess evidence about its state, and determine which interactions or observations are physically applicable.","scope":{"in":["Positive invariant mass and its distinction from energy, momentum, weight, and effective mass","Elementary or composite particle identity and applicable species relationships","Relativistic energy, momentum, velocity, and reference-frame dependence","Interaction properties relevant to production, detection, scattering, and binding","Stability, decay, and evidence supporting identification as a massive particle"],"out":["Massless particles as kinds in their own right","Quasiparticles whose effective mass describes behavior in a medium","Macroscopic bodies and continuous material distributions","Detailed taxonomies and decay tables owned by individual particle-species models","Detector engineering and complete experimental apparatus models","General theories of mass generation and spacetime geometry"],"boundaries":[]},"distinguishingFeatures":["The defining criterion is positive invariant mass, not merely nonzero energy or momentum.","For a free on-shell particle, measured energy and momentum obey E² − p²c² = m²c⁴ with m > 0.","A free massive particle admits a rest frame and travels below the vacuum speed of light; an extremely relativistic massive particle can nevertheless have a speed experimentally indistinguishable from c.","Massive does not mean heavy: a very small positive invariant mass qualifies.","A composite particle can qualify, but a positive invariant mass calculated for several particles does not by itself establish a single composite particle."],"structure":{"bundles":[{"id":"massive-particle-identity","name":"Massive particle identity","description":"Establishes what qualifies as a massive particle and which physical entity the description concerns.","layers":[{"id":"positive-invariant-mass","name":"Positive invariant mass","description":"Captures the defining mass criterion and the meaning of the reported mass.","findings":[{"id":"mass-qualification","name":"Mass qualification","description":"Qualification requires positive invariant mass; total energy or a positive upper bound alone does not establish this.","questions":[{"text":"Does the reported quantity represent invariant mass, rest energy, a mass bound, or an effective parameter?","id":"mass-qualification-q01","kind":"definition"},{"text":"What measurement or established species assignment supports m > 0, and with what uncertainty?","id":"mass-qualification-q02","kind":"measurement"}]}]},{"id":"particle-boundary","name":"Particle boundary","description":"Separates a particle from a collection of particles or a medium-dependent excitation.","findings":[{"id":"entity-and-species","name":"Entity and species","description":"An elementary particle, a composite particle, and an unbound multiparticle system require different identity claims even when each has a positive invariant mass.","questions":[{"text":"Is this an elementary particle, a composite particle, or a multiparticle system being treated collectively?","id":"entity-and-species-q01","kind":"boundary"},{"text":"Which species model supplies the identity, and what evidence supports that assignment?","id":"entity-and-species-q02","kind":"provenance"}]}]}]},{"id":"relativistic-motion","name":"Relativistic motion","description":"Connects mass with frame-dependent motion and the applicability of free-particle kinematics.","layers":[{"id":"energy-momentum-consistency","name":"Energy-momentum consistency","description":"Records the quantities and assumptions needed to test the mass relation.","findings":[{"id":"on-shell-kinematics","name":"On-shell kinematics","description":"For a free on-shell particle, invariant mass is related to energy and momentum by E² − p²c² = m²c⁴.","questions":[{"text":"In which reference frame were energy and momentum measured, and what are their uncertainties and correlations?","id":"on-shell-kinematics-q01","kind":"measurement"},{"text":"Is the free on-shell description justified, or is this a bound-state constituent, virtual contribution, or medium-dependent excitation?","id":"on-shell-kinematics-q02","kind":"boundary"}]}]},{"id":"rest-frame-and-speed","name":"Rest frame and speed","description":"Determines the appropriate motion regime and use of rest-frame quantities.","findings":[{"id":"motion-regime","name":"Motion regime","description":"Massive free-particle kinematics permits a rest frame; the ratio of momentum to mc determines whether nonrelativistic approximations are suitable.","questions":[{"text":"What values of β and Lorentz factor follow from the measured momentum and assigned mass?","id":"motion-regime-q01","kind":"measurement"},{"text":"Does the required precision permit a nonrelativistic approximation, or must the agent use relativistic relations?","id":"motion-regime-q02","kind":"action"}]}]}]},{"id":"interactions-and-access","name":"Interactions and experimental access","description":"Identifies which interactions permit the particle to be produced, detected, or manipulated.","layers":[{"id":"interaction-properties","name":"Interaction properties","description":"Links particle identity and quantum numbers to applicable interaction models.","findings":[{"id":"coupling-and-response","name":"Coupling and response","description":"Charge, spin, and species-specific couplings determine possible responses to fields and matter.","questions":[{"text":"Which interaction quantum numbers and couplings are established for this particle or candidate?","id":"coupling-and-response-q01","kind":"definition"},{"text":"Which proposed field or material interactions are supported by those properties?","id":"coupling-and-response-q02","kind":"action"}]}]},{"id":"production-and-observation","name":"Production and observation","description":"Connects proposed access methods to kinematic feasibility and expected signatures.","findings":[{"id":"accessible-processes","name":"Accessible processes","description":"Production requires sufficient invariant energy and compatible conservation laws; observation depends on interaction signatures or decay products.","questions":[{"text":"Does the proposed initial state have sufficient invariant energy and compatible conserved quantities to produce the particle?","id":"accessible-processes-q01","kind":"action"},{"text":"Which signature would identify it: a track, energy deposition, time of flight, decay reconstruction, or missing four-momentum?","id":"accessible-processes-q02","kind":"measurement"}]}]}]},{"id":"persistence-and-transformation","name":"Persistence and transformation","description":"Describes stability, decay, and participation in bound systems.","layers":[{"id":"lifetime-and-decay","name":"Lifetime and decay","description":"Distinguishes proper lifetime from laboratory survival and records allowed transformations.","findings":[{"id":"survival-and-products","name":"Survival and products","description":"Lifetime evidence and decay-channel information determine whether to model propagation, prompt decay, or a stability limit.","questions":[{"text":"Is the proper lifetime measured, bounded, or unknown, and what supports any claim of stability?","id":"survival-and-products-q01","kind":"measurement"},{"text":"Which decay channels are established, and how do the measured boost and lifetime affect the expected observation location?","id":"survival-and-products-q02","kind":"action"}]}]},{"id":"binding-and-composition","name":"Binding and composition","description":"Records when the particle belongs to or constitutes a bound system.","findings":[{"id":"composite-mass-accounting","name":"Composite mass accounting","description":"A composite particle's invariant mass reflects total rest-frame energy and cannot generally be obtained by adding isolated constituent masses alone.","questions":[{"text":"Is the mass assigned to the whole composite particle or to one constituent within it?","id":"composite-mass-accounting-q01","kind":"boundary"},{"text":"How are binding and internal energy represented when relating composite mass to constituent properties?","id":"composite-mass-accounting-q02","kind":"definition"}]}]}]},{"id":"mass-evidence-and-limits","name":"Mass evidence and interpretive limits","description":"Preserves how mass and identity were inferred and where a simple particle description becomes inadequate.","layers":[{"id":"measurement-provenance","name":"Measurement provenance","description":"Retains the method, assumptions, and uncertainty behind reported properties.","findings":[{"id":"mass-inference","name":"Mass inference","description":"An inferred mass depends on the observables and analysis used; an unresolved result must remain distinguishable from evidence of positive mass.","questions":[{"text":"Which source and method produced the mass estimate or bound?","id":"mass-inference-q01","kind":"provenance"},{"text":"Which calibration, background, resolution, or theoretical assumptions materially affect the conclusion?","id":"mass-inference-q02","kind":"measurement"}]}]},{"id":"quantum-description-limits","name":"Quantum description limits","description":"Identifies cases requiring a mass distribution, state decomposition, or resonance convention.","findings":[{"id":"mass-state-interpretation","name":"Mass-state interpretation","description":"A single sharp mass may be inadequate for a superposition of mass eigenstates or an unstable resonance; the applicable state and mass convention must be explicit.","questions":[{"text":"Does the description concern a definite mass eigenstate, a superposition, or an unstable resonance?","id":"mass-state-interpretation-q01","kind":"definition"},{"text":"What state decomposition, mass convention, or width information is needed before applying single-mass kinematics?","id":"mass-state-interpretation-q02","kind":"boundary"}]}]}]},{"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.","layers":[{"id":"reported-evidence","name":"Reported evidence","description":"Findings from the breadth pass, kept separate from the structural claims.","findings":[{"id":"evidence-confidence-notes","name":"Check these first","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these check these first hold for the sense of massive particle this model covers, and on what evidence?","id":"evidence-confidence-notes-q01","kind":"provenance"}]},{"id":"evidence-kinds","name":"Kinds and varieties","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these kinds and varieties hold for the sense of massive particle this model covers, and on what evidence?","id":"evidence-kinds-q01","kind":"provenance"}]},{"id":"evidence-identifiers","name":"Identifiers and schemes","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these identifiers and schemes hold for the sense of massive particle this model covers, and on what evidence?","id":"evidence-identifiers-q01","kind":"provenance"}]},{"id":"evidence-real-world-use","name":"Real-world use","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these real-world use hold for the sense of massive particle this model covers, and on what evidence?","id":"evidence-real-world-use-q01","kind":"provenance"}]},{"id":"evidence-measurements","name":"Typical measurements","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these typical measurements hold for the sense of massive particle this model covers, and on what evidence?","id":"evidence-measurements-q01","kind":"provenance"}]},{"id":"evidence-failure-modes-and-hazards","name":"Failure modes and hazards","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these failure modes and hazards hold for the sense of massive particle this model covers, and on what evidence?","id":"evidence-failure-modes-and-hazards-q01","kind":"provenance"}]},{"id":"evidence-neighbours","name":"Neighbouring kinds and how to tell them apart","description":"Recalled without web access and unsourced; every item is a lead to verify.","questions":[{"text":"Which of these neighbouring kinds and how to tell them apart hold for the sense of massive particle this model covers, and on what evidence?","id":"evidence-neighbours-q01","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["Explain what a massive particle is and give established examples such as the electron or proton.","State measured masses with their source and uncertainty."],"mustNot":["Present a speculative particle as established without stating its status.","Claim that a massive particle can travel at or faster than light in vacuum.","Misstate whether a particle has zero or nonzero mass, as for neutrinos, without current evidence.","Use physics vocabulary to support pseudoscientific product or health claims."],"requiresHuman":["Publishing new mass measurements or claims of new particles.","Teaching material presented as authoritative to students."]},"ethics":{"considerations":["Physics terms are misused to lend false authority to scams and pseudoscience.","Overstating discoveries misleads the public and funders."],"affectedParties":["Students and the public","Researchers","Consumers of pseudoscientific products"]},"owners":{"steward":"Nobody owns the concept; physics collaborations answer for their measurements.","roles":[],"masterSystems":["Review of Particle Physics data tables"]},"relations":[{"target":"Q1621273","type":"parent","note":"registry parent class"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.massive-particle","Wikidata: Q2923525 (https://www.wikidata.org/wiki/Q2923525)"]},"properties":{"applicability":"required","items":["Invariant mass: kg or eV/c² with uncertainty, bounds, and mass convention","Particle identity and composition: Species or candidate identity; elementary, composite, or unresolved","Quantum-state description: Mass eigenstate, specified superposition, mixed state, or unresolved","Four-momentum: Energy in eV and three-momentum in eV/c, with reference frame and uncertainty","Speed: m/s or β = v/c, with reference frame and uncertainty","Interaction quantum numbers: Electric charge in units of e, spin in units of ℏ, and other species-relevant quantum numbers","Proper lifetime: s, measured value or lower bound; unknown where unestablished","Physical environment: Vacuum, medium, external field, bound system, or specified combination","Identification status: Established, candidate, hypothetical, excluded under stated assumptions, or unresolved"]},"recognition":{"applicability":"required","items":["Not seen directly; known by tracks, energy deposits or decays recorded in detectors.","In detector data, a massive particle moves slower than light and its momentum and energy imply its mass."]},"capabilities":{"applicability":"required","items":["Evaluate whether measurements support positive invariant mass, accounting for uncertainty and assumptions.","Transform energy and momentum between specified inertial frames and determine whether a rest-frame description applies.","Check whether a proposed production, scattering, or decay process satisfies kinematic constraints.","Select candidate detection methods from charge, interactions, lifetime, and expected kinematics.","Estimate propagation time and decay distance when the particle state and lifetime permit.","Link the particle to a species or composite-particle model while preserving unresolved identity."]},"hazards":{"applicability":"required","items":["Energetic particle radiation can damage tissue or electronics, depending on particle type, energy and exposure.","Particles that are radioactive or arise from radioactive material can present radiation hazards that positive rest mass alone does not establish.","Treating all massive particles as having the same interactions can produce incorrect detector interpretations or unsafe shielding assessments."]},"interfaces":{"applicability":"not-applicable","items":[]},"context":{"applicability":"required","items":["Massive particles are encountered in particle physics, nuclear physics, astrophysics and descriptions of ordinary matter.","The category is used to distinguish particles with positive invariant mass when analyzing energy, momentum and relativistic motion."]}},"sources":[{"title":"Wikidata item Q2923525: massive particle","url":"https://www.wikidata.org/wiki/Q2923525","note":"identity and sense of the item"},{"title":"Wikipedia: Massive particle","url":"https://en.wikipedia.org/wiki/Massive_particle","note":"general description of the item"}],"openQuestions":["Does the registry intend massive particle to include all composite particles and unstable resonances, or a narrower elementary-particle category?","Which existing Vercy models already own particle identity, relativistic kinematics, and species-specific interaction rules?","How should the catalogue represent flavor states that are superpositions of mass eigenstates without assigning an unjustified single mass?","Which mass conventions and evidence standards should be required for unstable resonances and candidate particles?","Where should the registry place medium-dependent excitations and effective-mass descriptions relative to this entry?"],"resources":{"spec":"/models/things/publications/thing-q2923525/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q2923525/spec.json"],"providers":["Codex"],"researchStatus":"unreviewed","generatedAt":"2026-09-12T11:11:08Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"filled","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"not-applicable","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-07T10:10:29+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass","interaction.interfaces":"No standard or regulatory classification applies solely because a particle has positive rest mass, since applicable requirements depend on its identity and use."},"score":1.0}}