Application of Conservation Laws

• What must all particle interactions obey?

  A set of conservation laws
• What are the conservation laws in particle interactions?

  • Charge, Q
  • Baryon number, B
  • Lepton number, L
  • Strangeness, S
  • Energy (or mass-energy)
  • Momentum
• Which conservation law does not need to be conserved in weak interactions?

  Strangeness
• By how much can strangeness change in weak interactions?

  0, +1, or -1
• What values can quantum numbers such as Q, B, L, and S take?

  Discrete values (0, +1, -1, 1/2)
• How can you determine if a particle interaction can occur?

  Check if quantum numbers are equal
• What happens if one quantum number is not conserved in an interaction?

  The interaction cannot occur
• What is the quark composition of the lambda nought particle (Λ)?

  uds quarks
• In the interaction involving the lambda nought particle, what is the conservation of charge?

  0 = -1 + 1 + 0
• What is the strangeness of the lambda nought particle (Λ)?

  -1
• What does the strangeness conservation equation show for the lambda nought particle interaction?

  -1 = 0 + 0 + 0
• What is the baryon number of the lambda nought particle (Λ)?

  +1
• What is the baryon number conservation equation for the lambda nought particle interaction?

  +1 = 0 + 0 + 0
• What is the lepton number of the lambda nought particle (Λ)?

  0
• What is the lepton number conservation equation for the lambda nought particle interaction?

  0 = 0 + (-1) + 1
• What is the conclusion regarding the interaction of the lambda nought particle?

  The interaction is not permitted
• What is the equation for β decay?

  • The equation involves quark transformations
  • Charge must be conserved

  
• What will be provided for exotic particles in exam questions?

  Quantum numbers
• Where can other quantum numbers be found during an exam?

  On the datasheet or deduced