Theory lecture 7
5 Abril 2023, 08:30 • João Nuno Ramalho Gonçalves Pires
Symmetries in Particle Physics
- Discrete symmetries and Unitary operators: Parity conservation in QED and QCD
- Continuous symmetries: Translational invariance and linear momentum conservation
- Review of group theory
- Symmetry groups U(N) and SU(N)
- U(1) group and local U(1) gauge symmetry of quantum electrodynamics
- SU(2) and SU(3) symmetry groups for gauge theories of the electroweak and the strong interaction in the Standard Model
- Approximate flavour symmetry of the strong interaction SU(2) u/d Isospin symmetry
- Combining quarks to form meson and baryon states of the approximate isospin SU(2) symmetry
- Ground state baryon wavefunctions: wavefunction for a spin-up proton
- Extension of isospin symmetry to include the strange quark: SU(3) flavour symmetry
- Meson Octets and Singlets of flavour SU(3)
- Baryon Decuplets and Octects of flavour SU(3)
Recommended reading: Chapter 9 of Mark Thomson's book, Chapter's 4, 5.8-5.10 of D. Griffiths book