BRAINCAKEParticle Interaction Questions
Exam questions usually give an interaction and ask whether it is possible, or ask you to identify a missing particle. Use the same method every time.
Step 1: write the charge, baryon number and lepton number under every particle.
Step 2: total each quantity on both sides.
Step 3: if any total differs, the interaction is impossible; name the law that is broken.
Step 4: for a decay, check energy too: the products must have less total rest mass than the parent.
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Key terms in this lesson
- baryon number
- A quantum number assigned +1 to baryons, -1 to antibaryons and 0 to other particles, conserved in every interaction.
- lepton number
- A quantum number assigned +1 to leptons, -1 to antileptons and 0 to other particles, conserved in every interaction.
More in Particle Physics
- Annihilation
- The Standard Model
- Quarks
- Leptons
- Baryons and Mesons
- Quark Composition of Hadrons
- Conservation Laws in Particle Interactions
- Charge, Baryon Number and Lepton Number
All 19 lessons in Particle Physics · All Edexcel A-level Physics topics