Checklist for VL-04:

slide 9:

(1)
Can you explain why mass terms in the Lagrangian density are no problem in 
QED? 

(2)
According to the SM gluons are massless objects. Do you know of experimental 
upper bounds of the mass of the gluon? 

(3)
Experiments of nuclear physics often make the point that 99% of the mass of 
the proton originates from binding energy and therefore is investigated in 
the context of nuclear physics. Are these guys true? Could binding energy 
lead to something like a proton mass if quarks were masseless? 

slide 10: 

(4)
Can you write down the transformation behavior of the lower SU(2)L component 
and thus the general transformation formular for a mass term given in slide 
10 explicitly? 

slide 13:
 
(5)
Do you know where the issue if renormalizability comes from? What is actually 
the relation between renomalizability and gauge symmetry?

slide 18:

(6)
What does it actually mean if a field has a non-zero vacuum expectation value?

slide 27f:

(7)
If a paticle is interpreted as an excitation of the field \phi. What does 
"excitation" mean in this context? Do we have an "excitation" of the field 
in its ground state with energy E0?

(8)
Why does it make sense to develop the theory around the minimum? What is this 
minimum?

(9)
What are the effectiv (phenomenological) differences between the two examples 
given in slide 27 and 28?

(10)
How would hte system in the exmaple on slide 28 decide what minimum to choose?

slide 34:

(11)
You can of course choose any other point in the degenerate minimum to develop 
you field. Do the exercise shown in the slides for a purely imaginary ground 
state and compare the outcomes.

slide 36:

(12)
In this slide the example of chiral symmetry in QCD is given, where the family 
of pions (pi+, pi- and pi0) can be interpreted as Goldstone bosons. What doses 
it mean for the symmetry if these pseudo Goldstone bosons have a small but 
still non-zero mass?

slide 46:

(13)
On this slide a suble remark is made: "Gage boson mass acquired by interaction 
with Higgs background field, ...". To be more concrete the coupling to what 
mathematical object in the Lagrangian density is it that results in the mass 
term? Consequently a given coupling to the Higgs field implies the same coupling 
structure to the Higgs particle.