There are many different types of particle apart from your usual ones. They only appear in cosmic rays and in particle accelerators, they decay very quicklyso they're difficult to get a handle on.
- Hadrons are particles that feel the strong nulear force (or strong nuclear interaction).
- Eg, protons are positive so they need at strong force to hold them together.
- Hadrons are not fundamental particles, they are made up of smaller particles called quarks (see quark notes).
- Hadrons can be subdivided into two groups: baryons and mesons. They are lassified by the number of quarks they contain.
- Protons and neutons are baryons.
- All baryons are unstable apart from the proton. This means they decay to become different particles.
- The particle they end up as depends on what the baryon was before it decayed, but it ALWAYS include as proton.
- Some theories predict that protons should decay with a VERY long half-life but there is no evidence for it at the moment.
- Antiprotons and antineutrons are antibayrons.
- you don't find antibayons in ordinary matter.
- The number of bayons in an interaction is called the baryon number.
- Baryons (protons and neutrons) have a baryon number of +1.
- Antibaryons (antiprotons and antineutrons) have a baryon number of -1.
- Other baryons are given…