Can anyone help me with the expansion of the integral(adsbygoogle = window.adsbygoogle || []).push({});

[tex]I_{\mu\nu}=\int d^{4}l\frac{4l_{\mu}l_{\nu}-g_{\mu\nu}l^2}{(l^{2}-B+i\epsilon)^{3}}[/tex].

I would like to know how it could be expanded into two terms

[tex]I_{\mu\nu}=\frac{1}{2}\int d^{4}l\frac{\partial^2}{\partial l^\mu \partial l^\nu}\frac{1}{l^{2}-B+i\epsilon}-g_{\mu\nu}\int d^{4}l\frac{B}{(l^{2}-B+i\epsilon)^{3}}[/tex]-.

Another question is how can i calculate the first term to have result

[tex]-g_{\mu\nu}i\pi^{2}/2[/tex].

P.S. I am inexperienced with tensor calculations. I would be grateful for any help.

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# Expansion of nonregularized integral

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