diff --git a/.cspell.json b/.cspell.json
index 4a68c217..983eca55 100644
--- a/.cspell.json
+++ b/.cspell.json
@@ -231,11 +231,13 @@
     "ipyplot",
     "ipython",
     "ipywidgets",
+    "isdigit",
     "isinstance",
     "isnan",
     "isort",
     "jaxlib",
     "joinpath",
+    "jpsi",
     "juliaup",
     "jupyterlab",
     "kernelspec",
diff --git a/docs/conf.py b/docs/conf.py
index e962eff9..214f19a9 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -192,6 +192,7 @@ def get_nb_exclusion_patterns() -> list[str]:
     ),
     "numba": ("https://numba.pydata.org/numba-doc/latest", None),
     "numpy": (f"https://numpy.org/doc/{pin_minor('numpy')}", None),
+    "pdg": ("https://pdgapi.lbl.gov/doc", None),
     "plotly": ("https://plotly.com/python-api-reference/", None),
     "pwa": ("https://pwa.readthedocs.io", None),
     "python": ("https://docs.python.org/3", None),
diff --git a/docs/report/028.ipynb b/docs/report/028.ipynb
new file mode 100755
index 00000000..60417923
--- /dev/null
+++ b/docs/report/028.ipynb
@@ -0,0 +1,453 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "```{autolink-concat}\n",
+    "```"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": [
+     "PDG"
+    ]
+   },
+   "source": [
+    "::::{margin}\n",
+    ":::{card} Example of how to query the PDG Python API for decay\n",
+    "TR-028\n",
+    "^^^\n",
+    "This report shows how to search all known decays in the PDG using [its new Python API](https://pdgapi.lbl.gov/doc) and search three-body decays that have three equal particles in the final state.\n",
+    "+++\n",
+    "🚧 [compwa.github.io#271](https://github.com/ComPWA/compwa.github.io/issues/271)\n",
+    ":::\n",
+    "::::"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "source": [
+    "# PDG Python API: decay query"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": [
+     "remove-cell"
+    ]
+   },
+   "outputs": [],
+   "source": [
+    "%pip install -q pdg==0.0.6 tqdm==4.66.2"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": [
+     "remove-cell"
+    ]
+   },
+   "outputs": [],
+   "source": [
+    "from __future__ import annotations"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "outputs": [],
+   "source": [
+    "import pdg\n",
+    "\n",
+    "PDG = pdg.connect()"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "source": [
+    "This creates a [`PdgApi`](https://pdgapi.lbl.gov/doc/pdg.api.html#pdg.api.PdgApi) instance containing the following type of objects:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "outputs": [],
+   "source": [
+    "{type(obj) for obj in PDG.get_all()}"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "source": [
+    "In this example, we ask the question **which particles can decay to a final state with three equal particles?** For this, we use [`PdgBranchingFraction`](https://pdgapi.lbl.gov/doc/pdg.decay.html#pdg.decay.PdgBranchingFraction)s, which contain information about particle decays in their [`description`](https://pdgapi.lbl.gov/doc/pdg.data.html#pdg.data.PdgData.description):"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    }
+   },
+   "outputs": [],
+   "source": [
+    "jpsi_decay = PDG.get(\"M070.313/2023\")\n",
+    "type(jpsi_decay)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "outputs": [],
+   "source": [
+    "jpsi_decay.description"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "source": [
+    "So, let's pull all the decay descriptions from the PDG and do some clean up with {meth}`str.strip` and {obj}`set`:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "outputs": [],
+   "source": [
+    "from pdg.decay import PdgBranchingFraction\n",
+    "\n",
+    "all_decays = {obj for obj in PDG.get_all() if isinstance(obj, PdgBranchingFraction)}\n",
+    "decay_descriptions = {dec.description.strip() for dec in all_decays}\n",
+    "len(decay_descriptions)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "source": [
+    "To get more insight into the decay products, we create a new {obj}`set` of decay descriptions, but now describe each item as an initial state with a {obj}`tuple` of decay products. We again have to do a bit of cleaning here. The final state description sometimes contains digits, like `\"3pi0\"`, which we want to be rendered as `(\"pi0\", \"pi0\", \"pi0\")`.\n",
+    "\n",
+    "Note that we decay all state descriptions in the decay chain into account. For example,\n",
+    "```python\n",
+    "\"J/psi(1S) --> rho(1700) pi --> pi+ pi- pi0\"\n",
+    "```\n",
+    "\n",
+    "has two 'final' states:\n",
+    "```python\n",
+    "(\"rho(1700)\", \"pi\")\n",
+    "(\"pi+\", \"pi-\", \"pi0\")\n",
+    "```"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "editable": true,
+    "jupyter": {
+     "source_hidden": true
+    },
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": [
+     "hide-input"
+    ]
+   },
+   "outputs": [],
+   "source": [
+    "def create_final_state(description: str) -> tuple[str, ...]:\n",
+    "    items = []\n",
+    "    for particle in description.split():\n",
+    "        particle = particle.strip()\n",
+    "        if particle in {\"\", \",\"}:\n",
+    "            continue\n",
+    "        multiplier = particle[0]\n",
+    "        if multiplier.isdigit():\n",
+    "            particles = int(multiplier) * particle[1:]\n",
+    "            items.extend(particles)\n",
+    "        else:\n",
+    "            items.append(particle)\n",
+    "    return tuple(sorted(items))\n",
+    "\n",
+    "\n",
+    "decays: set[tuple[str, tuple[str, ...]]] = set()\n",
+    "for description in decay_descriptions:\n",
+    "    initial_state, *final_states = description.split(\" --> \")\n",
+    "    initial_state = initial_state.strip()\n",
+    "    for final_state in final_states:\n",
+    "        decays.add((initial_state, create_final_state(final_state)))\n",
+    "len(decays)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "source": [
+    "Now selecting the three-body decays is an easy matter using filters on comprehensions."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "outputs": [],
+   "source": [
+    "three_body_decays = {\n",
+    "    (initial_state, final_state)\n",
+    "    for initial_state, final_state in decays\n",
+    "    if len(final_state) == 3\n",
+    "}\n",
+    "len(three_body_decays)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "outputs": [],
+   "source": [
+    "equal_state_3body_decays = {\n",
+    "    (initial_state, final_state)\n",
+    "    for initial_state, final_state in three_body_decays\n",
+    "    if len(set(final_state)) == 1\n",
+    "}\n",
+    "sorted(equal_state_3body_decays)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "source": [
+    "Finally, and optionally, we can filter out final states that are not well defined, such as `g g g`, by checking whether they are defined in the PDG database."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "editable": true,
+    "jupyter": {
+     "source_hidden": true
+    },
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": [
+     "hide-input"
+    ]
+   },
+   "outputs": [],
+   "source": [
+    "for initial_state, final_state in sorted(equal_state_3body_decays):\n",
+    "    try:\n",
+    "        for name in (initial_state, *final_state):\n",
+    "            PDG.get_particle_by_name(name)\n",
+    "    except ValueError:\n",
+    "        pass\n",
+    "    else:\n",
+    "        print(f\"{initial_state:>20} → {' '.join(final_state)}\")"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "source": [
+    ":::{warning}\n",
+    "Not all final state in the [`description`](https://pdgapi.lbl.gov/doc/pdg.data.html#pdg.data.PdgData.description)s can be programmatically deciphered as individual particles. One could try to use [regular expressions](https://docs.python.org/3/howto/regex.html), but it's hard to cover all cases. Consider for instance the following case which contains $S$ and $D$ waves.\n",
+    ":::"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "outputs": [],
+   "source": [
+    "[dec for dec in decay_descriptions if dec.startswith(\"a_1(1260)\")]"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "source": [
+    "Additionally, not all decays seem to be included. Here is an attempt to find $J/\\psi \\to \\pi^0 \\pi^0 \\pi^0$."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "editable": true,
+    "jupyter": {
+     "source_hidden": true
+    },
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": [
+     "hide-input"
+    ]
+   },
+   "outputs": [],
+   "source": [
+    "import re\n",
+    "\n",
+    "sorted(\n",
+    "    decay\n",
+    "    for decay in decay_descriptions\n",
+    "    if decay.startswith(\"J/psi\") and re.match(r\".*(3 ?pi|pi.*pi.*pi).*\", decay)\n",
+    ")"
+   ]
+  }
+ ],
+ "metadata": {
+  "colab": {
+   "toc_visible": true
+  },
+  "kernelspec": {
+   "display_name": "Python 3 (ipykernel)",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.10.14"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 4
+}