"pi meson" meaning in English

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      "name": "compound"
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  "etymology_text": "From pi (“π”) + meson.",
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      "form": "pi mesons",
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  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
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          "ref": "2012 March-April, Jeremy Bernstein, “A Palette of Particles”, in American Scientist, volume 100, number 2, page 146:",
          "text": "There were also particles no one had predicted that just appeared. Five of them […, i]n order of increasing modernity, […] are the neutrino, the pi meson, the antiproton, the quark and the Higgs boson.",
          "type": "quote"
        }
      ],
      "glosses": [
        "A pion, a type of meson"
      ],
      "hyponyms": [
        {
          "word": "pi-plus"
        },
        {
          "word": "pi-minus"
        },
        {
          "word": "pi-zero"
        }
      ],
      "id": "en-pi_meson-en-noun-AYpwkl0a",
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        [
          "pion",
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        [
          "meson",
          "meson"
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      "raw_glosses": [
        "(archaic, formal) A pion, a type of meson"
      ],
      "synonyms": [
        {
          "word": "pion"
        },
        {
          "word": "πon"
        },
        {
          "word": "π-on"
        },
        {
          "word": "π"
        },
        {
          "word": "π meson"
        },
        {
          "word": "π-meson"
        },
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          "word": "pi-meson"
        }
      ],
      "tags": [
        "archaic",
        "formal"
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    }
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  "word": "pi meson"
}

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    }
  ],
  "etymology_text": "From pi (“π”) + meson.",
  "forms": [
    {
      "form": "pi mesons",
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      "word": "pi-minus"
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      "word": "pi-zero"
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  "lang_code": "en",
  "pos": "noun",
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      ],
      "glosses": [
        "A pion, a type of meson"
      ],
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        "(archaic, formal) A pion, a type of meson"
      ],
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  "synonyms": [
    {
      "word": "pion"
    },
    {
      "word": "πon"
    },
    {
      "word": "π-on"
    },
    {
      "word": "π"
    },
    {
      "word": "π meson"
    },
    {
      "word": "π-meson"
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      "word": "pi-meson"
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  "word": "pi meson"
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