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            "citation": "Chadwick, Possible Existence of a Neutron, Nature 129, 312 (27 February 1932); retyped one-page text",
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        "description": "This record begins with the February 1932 letter, which states its evidence and remaining uncertainty. It is distinct from the longer June report and later neutron theory. Bothe, the Joliot-Curies and Feather’s experimental roles are acknowledged in the source; they are not added to the letter’s byline. WRS has not reproduced the measurements.",
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          "citation": "Chadwick, Possible Existence of a Neutron, Nature 129, 312 (27 February 1932); retyped one-page text",
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      "statement": "# Chadwick: evidence for the neutron\n\nInterpreted recoil measurements from penetrating beryllium radiation as evidence for a neutral particle with mass close to the proton, testing that account against the high-energy photon alternative.\n\n## Scientific scope\n\nThis record begins with the February 1932 letter, which states its evidence and remaining uncertainty. It is distinct from the longer June report and later neutron theory. Bothe, the Joliot-Curies and Feather’s experimental roles are acknowledged in the source; they are not added to the letter’s byline. WRS has not reproduced the measurements.\n\n## Reading status\n\nThis is a source-linked WRS catalogue note. A full explanatory guide and independent scientific reconstruction have not been completed for this entry. Read the identified original work for its complete narrative and arguments.\n\n## People and systems\n\nJames Chadwick\n\nListed source contributors; individual labor shares are not measured\n\n\n\n## Original sources\n\n- [Chadwick, Possible Existence of a Neutron, Nature 129, 312 (27 February 1932); retyped one-page text](https://principia.io/media/uploads/pdf/chadwick_pdf.pdf)\n- [Nature: Possible Existence of a Neutron; DOI 10.1038/129312a0](https://www.nature.com/articles/129312a0)\n",
      "summary": "Interpreted recoil measurements from penetrating beryllium radiation as evidence for a neutral particle with mass close to the proton, testing that account against the high-energy photon alternative.",
      "title": "Chadwick: evidence for the neutron"
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    "title": "Chadwick: evidence for the neutron",
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    "track": "Scoped scientific or research-capability contribution",
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    "what_changed": "Interpreted recoil measurements from penetrating beryllium radiation as evidence for a neutral particle with mass close to the proton, testing that account against the high-energy photon alternative.",
    "scope": "Interpreted recoil measurements from penetrating beryllium radiation as evidence for a neutral particle with mass close to the proton, testing that account against the high-energy photon alternative. Scope limitation: This record begins with the February 1932 letter, which states its evidence and remaining uncertainty. It is distinct from the longer June report and later neutron theory. Bothe, the Joliot-Curies and Feather’s experimental roles are acknowledged in the source; they are not added to the letter’s byline. WRS has not reproduced the measurements.",
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        "title": "Chadwick, Possible Existence of a Neutron, Nature 129, 312 (27 February 1932); retyped one-page text",
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