It is now possible to state that the Standard Model is a gauge theory invariant under symmetry group given by the direct product of the symmetry group of the strong interaction, , with that of electroweak interaction, which also contains the symmetry group of electromagnetic interaction . The general form involving these fields is where: indicate leptons … Continue reading So, what about the Standard Model?

# hadrons

# Why a standard model? Some fundamentals

Until 1945, particle physics was mostly based on the study of cosmic rays. The turning point came with the advent of accelerators and the subsequent particle proliferation. Elementary (to our knowledge) particles can be classified according to their spin statistics, and thus in order to whether they participate in strong interactions, as shown in the Table: Strongly interactive particles are … Continue reading Why a standard model? Some fundamentals

# Strong Interactions and quarks

Quantum chromodynamics (QCD) is the gauge theory describing strong interactions between quarks. It constitutes a fundamental theory within the Standard Model and it is responsible for the portion. Weak and electromagnetic interactions are considered unified in the single symmetry group where , the weak hypercharge, is the generator of the group that is given by … Continue reading Strong Interactions and quarks