ParticlePhysics MCP Server

A Model Context Protocol server that lets Claude Desktop, IDEs, and other MCP clients

look up particle properties and decay modes.

Supports natural-language queries (`muon plus`, `pion zero`, `antiproton`, `anti up quark`),

case-insensitive lookup, MC IDs (`-13`), and returns both human-readable text and a

structured JSON payload.

Table of Contents

• Features
• Install
• Configure your MCP client
• Tools
  • `search_particle`
  • `list_decays`
• Changelog
• Maintainer
• License

Features

• `search_particle` — mass (MeV + GeV), charge, spin, color, parity / C / I / G,

lifetime or width, MCID, review ID

• `list_decays` — exclusive / inclusive branching fractions with the source method named
• Natural-language input — `muon plus`, `positive tau`, `pion zero`, `kaon minus`
• Anti-particle support — `antimuon`, `anti up quark`, `ubar`, `u bar`, `u_bar`, `u~`,

`antineutron`; resolved via MCID negation, no name guessing

• MC ID lookup — query directly with `11`, `-2212`, etc.
• Self-conjugate aware — `anti photon` resolves to `gamma`, `anti pi0` to `pi0`
• Structured output — every response includes a fenced ` ```json ` block alongside

the human-readable text

Install

git clone https://github.com/uzerone/particlephysics-mcp-server.git
cd particlephysics-mcp-server
pip install -e .

Configure your MCP client

Add one of the following to your client's MCP config (e.g. `claude_desktop_config.json`).

Using `uvx` from the cloned repo (no global install needed):

{
  "mcpServers": {
    "particlephysics": {
      "command": "uvx",
      "args": ["--from", "/absolute/path/to/particlephysics-mcp-server",
               "python", "-m", "particlephysics_mcp_server"]
    }
  }
}

Using a local virtualenv (after `pip install -e .`):

{
  "mcpServers": {
    "particlephysics": {
      "command": "/absolute/path/to/.venv/bin/python",
      "args": ["-m", "particlephysics_mcp_server"]
    }
  }
}

Tools

`search_particle`

Sample call: `search_particle({"query": "muon plus"})`

Found 1 particle(s) matching 'muon plus':

1. mu
   Name: mu+
   PDG ID: -13
   PDG Review ID: S004/2025
   Mass: 105.6583755 MeV (0.1056583755 GeV)
   Spin (J): 1/2
   Charge: 1
   Color: singlet
   Quantum numbers: J=1/2
   Lifetime: 2.196981148893498e-06

{

"query": "muon plus",

"count": 1,

"particles": [{

"name": "mu+",

"mcid": -13,

"pdg_review_id": "S004/2025",

"mass": {"mev": 105.6583755, "gev": 0.1056583755},

"charge": {"value": 1.0, "fraction": "1"},

"spin": "1/2",

"color": {"multiplicity": 1, "label": "singlet"},

"quantum_numbers": {"J": "1/2"},

"lifetime": {"seconds": 2.197e-06, "stable": false, "text": "..."}

}]

}

// Code block

`list_decays`

Same identifier formats as `search_particle`. Tries `exclusive_branching_fractions` →

`branching_fractions` → `inclusive_branching_fractions` and reports which source it used.

Returns an empty decay list with `stable=true` for stable particles.

Sample call: `list_decays({"particle_id": "tau"})`

Decay modes for particle 'tau':

1. tau- --> mu- nubar_mu nu_tau (BR: 17.39 ± 0.04 %)
2. tau- --> e- nubar_e nu_tau  (BR: 17.82 ± 0.04 %)
…

{

"particle": {"name": "tau-", "mcid": 15, ...},

"source": "exclusive_branching_fractions",

"count": 137,

"decays": [{

"description": "tau- --> mu- nubar_mu nu_tau",

"branching_ratio_text": "17.39 ± 0.04",

"value_text": "17.39E-2",

"is_limit": false

}, ...]

}

// Code block

Changelog

See CHANGELOG.md for release notes.

Maintainer

@uzerone

License

MIT — see LICENSE.txt.