Sunset / sunrise diagrams in 2D

[nidnus]

Hi,

Can anyone point me to a reference where the complete amplitude for a sunrise diagram in 2D with generally different masses is written down. That is, I want the value of the following integral

$$ \int d^2k d^2l \frac{1}{(k^2-m_1^2)(l^2-m_2^2)((p-k-l)^2-m_3^2)}

$$

where p is the external momentum. For equal masses the answer is simple while it seem to be more complicated for generic masses. I'm especially interested in the case where some of the masses are equal and others are zero.

Thanks

 

[Finbar]

What theory is it?

 

[nidnus]

Doesn't really matter. The integral is as stated above. If you want to you can think about it as phi four theory in 2D.