(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Hi. For the question given (attachment) where does the factor of 2PI in the function for sigma come from in the first step because I don't get it in my working for the first step.

2. Relevant equations

see attachment

3. The attempt at a solution

I got sigma (without the 2PI) by changing variable to t =cos theta, thus integrating between minus and plus 1

and using m=n in the legendre polynomial,

so I am wondering if the 2PI came from integrating over the phi dependence as we are dealing with scattering from a radial potential?

I also need prodding in the right direction for the next step!

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# Homework Help: Optical Theorem

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