LOG#063. SM(V): Gauge fixing.

Gauge theories require that we select “a gauge” in order to calculate physical observables. That is, you have to fix the gauge to eliminate field configurations that are physically equivalent ( they can not be distintinguished, as field configurations). The … Continue reading

LOG#062. SM(IV): SSBEW&Higgs.

We have seen that the SM, under general considerations such as gauge invariance and renormalizability, does NOT initially allow EXPLICIT mass terms in the lagrangian framework for the gauge bosons AND/OR the chiral fermions. Note that every SM fermions is … Continue reading

LOG#061. SM (III): EW sector.

The above picture is the EW lagrangian! Is it simple? Is it beautiful? It depends on your taste! It is called the GSW (Glashow-Salam-Weinberg) lagrangian. The electroweak (EW) part/theory is based on the gauge symmetry group. Before spontaneous symmetry breaking, … Continue reading

LOG#060. SM (II): The QCD sector.

QCD or Quantum ChromoDynamics acts on quarks and hadrons (both baryons and mesons, “colored” particles). There are lots of baryons and mesons, and I have listed some of them in the two tables above as “an apetizer”. Please, remeber that … Continue reading

LOG#057. Naturalness problems.

In this short blog post, I am going to list some of the greatest “naturalness” problems in Physics. It has nothing to do with some delicious natural dishes I like, but there is a natural beauty and sweetness related to … Continue reading