Problem sets for Physics 230C winter 2012
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Note: The most recent problem set appears first.
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Problem set 4  
due Tuesday, Mar. 20

1) g-2 problem by J. Gunion in the Resources on our Smartsite.

2) Ghost mass. In discussing the renormalization of SU(N),
we did not mention the need for a ghost mass counterterm.
What is the ghost mass at tree level? 
What are one loop diagrams that give a ghost self-energy correction?
What contribution do they give to the ghost mass?
Comment or speculate on why your result came out the way that it did.

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Problem set 3  
due at the start of class      Tuesday, Mar. 6

See p_set_3 in the Resources on our Smartsite.

This is long and far from trivial, but it's rewarding. 
I'm open to your input on when to make it due. 
No matter when it's due, you should start working on it NOW. 

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Problem set 2  Due start of class Thursday, Feb. 9 

Consider scalar field theory with interaction term 
phi^3 in 6 dimensional space time. 
Follow the general methods used for for phi^4 in 
4 dimensions in Gunion. 

For phi^3 in 6 dimensions:
What does power counting say about the primitive divergences?
Give the formal structure of the renormalization.
What is the general relation between the bare and renormalized quantities?
What counterterms are needed?
Give the Lagrangian in terms of both the bare and renormalized quantities.   
Do the explicit calculations for the one loop renormalization of the coupling for the phi^3 term.
Compute the one loop beta function. 
Do not overlook the need to include 
the wave function renormalization for this theory.
Use the beta function and the RG equation to get 
lambda(mu), i.e. the coupling as a function of the 
scale.

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Problem set 1  
due at the start of class Tuesday, Jan. 24

See ps_1 in the Resources on our Smartsite.
 
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