Mellin transform of the term proportional to q_αq_β

tensor[1] = u^(d + z + 4)/2Gauss[4]

2^(-2 - d) ^(-Abs[x]^2/(4 u)) π^(-d/2) u^(-2 - d/2 + 1/2 (4 + d + z)) (2 u K[α, β] - x[α] x[β])

tensor[2] = PowerExpand[Integrate[tensor[1]/u, {u, 0, Infinity}, GenerateConditionsFalse]]/.a_^b_a^Expand[b]

2^(-3 - d - z) π^(-d/2) Abs[x]^z (Abs[x]^2 Gamma[-1 - z/2] K[α, β] - 2 Gamma[-z/2] x[α] x[β])

Created by Mathematica  (March 14, 2006)