physics paper 1

• Particle groups


  • Hadrons
  • Leptons
• Leptons


  Fundamental particles including electron, muon (heavy electron), and neutrino (no charge)
• Lepton number


  Leptons have a lepton number of 1, their antiparticles have a lepton number of -1
• Neutrinos


  Can be electron neutrinos or muon neutrinos, with their own lepton numbers
• Quark flavours


  • Up
  • Down
  • Strange
• Quark charges


  Up (+2/3), Down and Strange (-1/3)
• Strangeness


  Strange quarks have strangeness -1, antistrange +1
• Baryon number

  Baryons have a baryon number of +1 or -1 if they contain antiquarks
• Neutrons are up-down-down, protons are up-up-down