Complex integral coming from a 1loop diagram

In summary, the conversation was about studying the divergent/convergent behavior of Feynman diagrams in Luttinger liquids. The focus was on a particular loop integral that has a specific form and involves the total energy, momentum, and Fermi velocity of incoming fermions. The individual was seeking help with computing this integral and suggested using partial fractions decomposition. They also mentioned finding that the coefficients in the decomposition do not depend on certain variables, but wanted to make sure there were no mistakes.
  • #1
AdeBlackRune
9
0
Hi,
i'm studing the divergent/convergent behavior of some feynman diagrams that emerge from the study of luttinger liquid. One of this diagrams has a loop inside it and loop-integrals has the following form:

[itex]\int_{-\Lambda}^{+\Lambda}dQ\int d\Omega\frac{1}{(\omega-\Omega)-iv(k-Q)}\frac{1}{\Omega-ivQ}[/itex]


where [itex]\omega[/itex]
and k are total energy and momentum of the incoming fermions and v the Fermi velocity. Could someone help me with the computation of this integral? It would not be hard but I'm blocked. The dQ integral is limited within a window [-L,+L]
 
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  • #2
You can perform a partial fractions decomposition of the term:

$$\frac{1}{\omega-\Omega - i v(k-Q)}\frac{1}{\Omega - ivQ} = \frac{A}{\omega-\Omega - i v(k-Q)} + \frac{B}{\Omega - ivQ}.$$

I found that A and B end up not depending on ##\Omega## or ##Q##, but double check that I didn't make an error.
 

Related to Complex integral coming from a 1loop diagram

1. What is a complex integral in the context of a 1-loop diagram?

A complex integral in the context of a 1-loop diagram is a mathematical calculation used to evaluate the contributions of virtual particles in a quantum field theory calculation. It involves integrating over complex numbers, which allows for a more precise and accurate calculation of the loop diagram.

2. How does a 1-loop diagram contribute to a quantum field theory calculation?

A 1-loop diagram represents the interactions of virtual particles in a quantum field theory. These interactions can lead to corrections in the calculations of physical quantities, such as particle masses or scattering amplitudes. The complex integral is used to accurately calculate these corrections.

3. What is the significance of the 1-loop diagram in particle physics?

The 1-loop diagram is significant in particle physics because it represents the first level of quantum corrections to the interactions of particles. These corrections play a crucial role in understanding the behavior of particles at high energies and can lead to important insights into the fundamental laws of nature.

4. How do you solve a complex integral coming from a 1-loop diagram?

Solving a complex integral coming from a 1-loop diagram involves using mathematical techniques such as contour integration and residue theorem. The specific method used will depend on the specific integral being evaluated and the desired level of precision.

5. What are some applications of complex integrals in 1-loop diagrams?

Complex integrals in 1-loop diagrams have a wide range of applications in particle physics, including calculations of particle masses, scattering amplitudes, and decay rates. They are also used in theoretical models to study the properties of new particles and interactions that may be observed in experiments.

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