# Is this an error in Srednicki?

Hi,

On p104 of Srednicki's QFT, he does an integral in closed form, equations 14.43 and 14.44. I just ran the calculations for this in Mathematica, and I get his answer exactly except for my constants $$c_1=4-\pi\sqrt{3}$$ and $$c_2=4-2\pi\sqrt{3}$$.

The mathematica code I used to generate this was:

In:= d[x_] := x*(1 - x)*k^2 + m^2

In:= d0[x_] := (1 - x*(1 - x))*m^2

In:= p[x_] = (1/2)*a*d[x]*Log[d[x]/d0[x]]

Out= 1/2 a (m^2 + k^2 (1 - x) x) Log[(m^2 + k^2 (1 - x) x)/(
m^2 (1 - (1 - x) x))]

In:= Integrate[p[x], {x, 0, 1},
Assumptions -> {Element[m, Reals], Element[k, Reals], m > 0, k > 0}]

Out= (1/(12 k Sqrt[
k^2 + 4 m^2]))a (k Sqrt[
k^2 + 4 m^2] (4 (k^2 + m^2) - Sqrt (k^2 + 2 m^2) \[Pi]) +
2 (k^2 + 4 m^2)^2 ArcTanh[k/Sqrt[k^2 + 4 m^2]])
Then collecting the terms in k^2 and m^2, you find the constants I posted above, rather than the very similar but different Srednicki ones.

It's not listed on his errata page if this is an error, perhaps I am missing something? just seems very close, to not be correct.

Oh sorry, I literally saw the second I pressed send, that he also subtracts a $$\tfrac{1}{12}\alpha (k^2+m^2)$$ in 14.43 that I left off.