Integral after alpha parametrization

[jd24680]

I have been stuck on the following double integral for some time:

∫(0 to inf) dα1 ∫(0 to inf) dα2 a1^(n1) * exp(-i (α1+α2) m^2) * (α1+α2)^(n2)

which arose after using alpha paremetrization on a Feynman integral. I was advised by my supervisor to use the substitution α1 = 1/2 (t+u) and α2 = 1/2 (t-u) but after doing this I fail to see how it helps.

Any advice on how to do this?

Thanks.

 

[SteamKing]

Show your work using the recommended substitutions. Perhaps you made an error in your algebra.