Standard Model Particle Zoo: PDG Data and Conservation Laws
An interactive Standard Model reference and conservation-law checker. The chart lays out the three generations of quarks and leptons, the gauge bosons and the Higgs, coloured by type, with the PDG mass, charge, spin, baryon and lepton numbers and the forces each feels; a force filter dims the particles that do not feel a chosen interaction. The decay panel takes a parent and its daughters and checks the additive conservation laws (electric charge, baryon number, the three lepton-flavour numbers) and the kinematic Q-value, so the allowed decays (muon, neutron beta, charged-pion, neutral-pion, tau) pass while the lepton-flavour-violating $\mu \to e \gamma$ and the kinematically forbidden $p \to n \pi^+$ are rejected. Every catalogued real decay conserves charge, baryon number and lepton flavour with a positive Q-value (neutron beta about 0.782 MeV), while the lepton-flavour-violating $\mu \to e \gamma$ and the kinematically forbidden $p \to n \pi^+$ are correctly rejected, and leptons feel no strong force.
WHAT TO TRY
- Set the force filter to strong, electromagnetic or weak: particles that do not feel the chosen interaction dim out. Only quarks light up under strong, only charged particles under electromagnetic.
- Pick a decay and read the checker: it tests baryon number, lepton number, charge and energy conservation. A forbidden decay fails a specific conservation law, named on the panel.
- Compare the three generations: same charges and spins, rising masses. The Standard Model gives no reason for three copies, which is one of its open puzzles.