IB DP Physics: HL复习笔记7.3.7 The Standard Model of Particle Physics

The Higgs Boson

  • The Higgs-boson was predicted in 1964
    • The prediction included an approximate mass for the particle, at 125 GeV c2
  • This prediction came from the standard model, which required the photon, W and Z bosons to be massless
    • While the photon is indeed massless, both the W and Z bosons have large masses
    • This did not align with the standard model unless mass is not a property of the particle, but a property of space
    • The field that gives particles their mass is known as the Higgs-field and the particle associated with this field is the Higgs-boson
  • The Higgs-boson was eventually discovered in 2012 at CERN’s Large Hadron Collider (LHC) in Switzerland
  • The Higgs-boson is responsible for the mass of all other particles in the standard model
  • The quantum field theory that is responsible for this mechanism is beyond the scope of the IB DP Physics course
    • Understanding the Higgs-boson mechanism is deeply complex
    • However, the concept is an integral part of the standard model and particle physics

The Standard Model of Particle Physics

  • The standard model describes the fundamental particles that make up other sub-atomic particles
  • The standard model was developed through experimental discoveries and theoretical predictions
    • The latest addition to the standard model was the Higgs-boson which was confirmed in 2012
  • Particles are grouped into 4 major categories
    • The quarks
    • The leptons
    • The gauge bosons
    • The scalar bosons (or Higgs Boson)
  • The particles of the standard model are used to produce larger, non-fundamental particles such as protons and neutrons


The standard model of particle physics

  • The standard model explains a lot of the theory of physical interactions in our universe
  • Yet, the standard model does not explain
    • A complete relativistic theory of gravity
    • The existence and nature of dark matter
    • The existence and nature of dark energy and the expansion of the universe
  • There is still room for improvement on the standard model and scientists continue to seek further answers and refine the current model