LOG#065. SM(VII): phenomenology.

The above picture is a cool mind map by the cosmologist and particle physicist Sean Carroll. It summaries somehow the phenomenological charges of the Standard Model plus the gravitational sector we do not know at quantum level. Physical Higgs sector … Continue reading

LOG#064. SM(VI): total lagrangian.

The total SM lagrangian can be written now, with some subtle notational changes, from the previous posts. It is really a monster “thing”: From what you have learned in previous log-entries, can you identify the meaning of every lagrangian piece … Continue reading

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