Sumários

Introduction to QCD: Flavour symmetries

15 Abril 2020, 08:30 • Nuno Barros

  • Symmetries in Particle physics: Noether's theorem
  • Notions of group theory
  • Quark flavour symmetry
    • Isospin and SU(2)
    • Describing mesons from quarks
    • SU(3) and hyper charge
    • Light uds mesons
    • Building baryons wavefunctions
  • Introduction to QCD 
    • Basic principles of QCD : Local gauge principle
    • Color and color confinement

Discussion of the homework exercises (series 4)

3 Abril 2020, 08:30 • Nuno Barros

Discussion of the solutions of the exercises submitted the previous week. 

Discussion of the associated topics and answering of questions from students.

Debate about possible alternatives to implement evaluation methods without presence requirement. 

Deep inelastic scattering

1 Abril 2020, 08:30 • Nuno Barros

  • Deep inelastic scattering
    • Definitions of kinematic variables (Q^2, Bjorken x, y, v)
    • Elastic vs Inelastic scattering
    • Structure functions
    • Bjorken Scaling and Callan-Gross relation
  • Quark-Parton model
    • electron-quark scattering
    • Parton distribution functions
    • Valence and sea quarks
    • Measuring the PDFs. 
    • How to infer structure information from the PDFs.

Exercises on helicity and QED. Introduction to ep inelastic scattering

27 Março 2020, 08:30 • Nuno Barros

  • Discussion of homework 3
    • Helicity and CP operators
    • Feynman diagrams and Feynman rules for QED
    • Discussion of the exercises and associated topics
  • Introduction to ep inelastic scattering
    • Revision of ES
    • Discussion of the IS cross section
    • Structure functions and implications of the experimental results
    • Bjorken Scaling and Callan-Gross relation

Electron-positron annihilation. Chirality. electron-proton scattering.

25 Março 2020, 08:30 • Nuno Barros

  • QED example: electron-positron anihilation
    • Electron and muon currents
    • Spin-averaged matrix element squared
    • Differential and total cross section
  • Chirality
    • Spin considerations in e-e+ annihilation
    • Lorentz-invariant form of spin-averaged matrix element
    • Chirality
  • Electron-proton elastic scattering
    • Quick review of Rutherform/Mott scattering cross sections
    • e-p scattering as probe for structure of the proton
    • Introduction to form factors
    • Point-like elastic scattering
    • Rosenbluth formula
    • Measuring form factors from experimental data