Particle Physics Calculator

Explore the subatomic world with quantum mechanics and the Standard Model

kg
Rest mass of particle
Rest Energy (E₀)
8.19e-14
J
Equivalent Mass
9.109e-31
kg
In Electronvolts
511,000
eV
Particle Type
Electron
Standard Model
Mass-Energy Equivalence

E = mc² is the mass-energy equivalence formula from special relativity. It states that energy (E) and mass (m) are interchangeable, with c (speed of light) as the conversion factor.

  • c = 299,792,458 m/s (speed of light)
  • 1 eV = 1.602 × 10⁻¹⁹ J
  • Electron mass: 9.109 × 10⁻³¹ kg (0.511 MeV)
  • Proton mass: 1.673 × 10⁻²⁷ kg (938 MeV)
  • Neutron mass: 1.675 × 10⁻²⁷ kg (940 MeV)
Select a particle to calculate its decay
Half-life
2.20e-6
seconds
Mean Lifetime
3.28e-6
seconds
Decay Width
3.00e-10
eV
Decay Products
e⁻, ν̄e, νμ
Common decay channels
Decay Formulas
Half-life: t1/2 = ln(2) / λ
Mean lifetime: τ = 1 / λ
Decay width: Γ = ħ / τ
ħ = h / 2π = 6.582 × 10⁻¹⁶ eV·s
Kinetic energy of projectile
Center of Mass Energy
1.41
GeV
Cross Section
1.23e-31
m²
Interaction Probability
0.45
per collision
Luminosity
1e34
cm⁻²s⁻¹
e⁻
p⁺
Projectile
Target
Total energy of particle
Rest mass of particle
Lorentz Factor (γ)
1957
γ = 1/√(1 - v²/c²)
Velocity (v)
0.99999987
c
Momentum (p)
1.00
GeV/c
Kinetic Energy
0.999
GeV
Relativistic Kinematics

At high energies, particles approach the speed of light and exhibit relativistic effects:

  • Total energy: E = γmc²
  • Momentum: p = γmv
  • Kinetic energy: K = (γ - 1)mc²
  • Velocity: v = c √(1 - (mc²/E)²)
  • LHC protons: 6.5 TeV, γ ≈ 6,928
  • CERN LEP electrons: 104.5 GeV, γ ≈ 200,000
The Standard Model of Particle Physics

The Standard Model describes the fundamental particles and their interactions:

Quarks Leptons Force Carriers Higgs Boson
  • Fermions (matter particles):
    • Quarks: up, down, charm, strange, top, bottom
    • Leptons: electron, muon, tau, neutrinos
  • Bosons (force carriers):
    • Photon (electromagnetism)
    • W and Z bosons (weak force)
    • Gluons (strong force)
    • Graviton (gravity, hypothetical)
  • Higgs Boson: Gives mass to other particles
  • Four fundamental forces: gravity, electromagnetism, weak, strong
Key Particle Physics Formulas
E = γmc² (Total energy)
p = γmv (Relativistic momentum)
E² = p²c² + (mc²)² (Energy-momentum relation)
λ = h/p (de Broglie wavelength)
Γ = ħ / τ (Decay width)

Particle Physics Fundamentals

Particle physics studies the fundamental constituents of matter and the forces acting between them. At the smallest scales, particles behave according to quantum mechanics and special relativity.

Concept Description Key Equation
Relativistic Energy Total energy of a moving particle E = γmc²
Momentum Relativistic momentum p = γmv
Decay Law Exponential decay of particles N = N₀e⁻ᵗ/ᵀ
Heisenberg Uncertainty Limits on position and momentum Δx·Δp ≥ ħ/2
Schrödinger Equation Quantum wave function evolution iħ∂ψ/∂t = Ĥψ

Key Experiments in Particle Physics

  • Cathode Ray Tubes (1897): J.J. Thomson discovers the electron
  • Gold Foil Experiment (1911): Rutherford discovers the atomic nucleus
  • Cloud Chamber (1932): Anderson discovers the positron
  • Neutrino Detection (1956): First detection of neutrinos
  • Discovery of Quarks (1968): Deep inelastic scattering reveals proton structure
  • W/Z Boson Discovery (1983): CERN discovers carriers of weak force
  • Top Quark Discovery (1995): Fermilab confirms heaviest quark
  • Higgs Boson Discovery (2012): CERN completes Standard Model

Note: The Standard Model explains three of the four fundamental forces but does not include gravity. It also doesn't explain dark matter or dark energy.

Frequently Asked Questions

The Standard Model is the theory describing three of the four known fundamental forces (electromagnetic, weak, and strong interactions) and classifying all known elementary particles. It was developed throughout the latter half of the 20th century and has been experimentally verified with remarkable precision.

Quarks and leptons are the two fundamental types of matter particles (fermions) in the Standard Model. Quarks combine to form composite particles called hadrons (protons and neutrons). Leptons include electrons, muons, tau particles, and their associated neutrinos. Quarks participate in strong interactions, while leptons do not.

The Higgs boson is an elementary particle associated with the Higgs field, which gives mass to other fundamental particles. It was predicted by the Standard Model and discovered at CERN in 2012. The Higgs mechanism explains why some particles have mass while others (like photons) do not.

Particle accelerators use electromagnetic fields to propel charged particles to high speeds and contain them in well-defined beams. Large accelerators like the LHC at CERN accelerate particles to nearly the speed of light and collide them to study fundamental particles and forces. Detectors surrounding the collision points record the resulting particles.

Antimatter is composed of antiparticles, which have the same mass as ordinary particles but opposite charge and quantum numbers. When matter and antimatter meet, they annihilate each other, converting their mass into energy. Antimatter is produced in particle accelerators and in some radioactive decay processes.