Take the 2-minute tour ×
Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free, no registration required.

enter image description here

(Zoom in here to see the scales.)
About the result of plotting running of 3 coupling constant, we think that we should get the correct one(MSSM).

But we get discontinuity at $ M_{susy}$.

If there something wrong in our formulae? If you have the correct formulae of $1/\alpha$, please provide them for me.

share|improve this question

closed as too localized by Brandon Enright, akhmeteli, Waffle's Crazy Peanut, Qmechanic Jun 10 '13 at 12:05

This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question.

2  
Hi, you can find the full 2-loop beta functions in Martin and Vaughn here: arxiv.org/abs/hep-ph/9311340 –  sujeet Jun 10 '13 at 5:41
2  
I can't read the scales on your plot well enough to see whether they are different. –  Michael Brown Jun 10 '13 at 6:40

1 Answer 1

If you change the particle content of your theory, you need to take into account threshold corrections. In order to be consistent with two-loop running you should also calculate the one-loop threshold coefficients. I guess these will make up for your dicontinuity.

share|improve this answer
    
What is meant by "consistent" here? Is it "making up for discontinuity"? –  stupidity May 15 at 20:53
1  
No. "Consistent" here means that if you take into account corrections of order $\hbar^2$, you should take into account all corrections to $\hbar^2$, which includes the threshold corrections. –  Neuneck May 17 at 16:02
    
Ah I see they are of the same order. Thanks for clarifying. –  stupidity May 18 at 17:18

Not the answer you're looking for? Browse other questions tagged or ask your own question.