(\[opdef\]). The explicit tensors for each level are given in Appendix A together with the method which allows one to compute the amplitude itself via a projection onto the Green’s function with free indices. The same tensor basis and projection is used for each level. The total number of projectors, $n_i$, is different for each level and recorded in Table $1$. It is worth noting that the basis of projection tensors which we use for each level is not unique. They are constructed from the basic momentum vectors, $\gamma$-matrices and metric tensors available, in such a way that each final tensor has the same symmetry structure as its associated operator insertion, as well as being traceless in $d$-dimensions. However, to construct all the tensors in each set of projectors we have isolated all the basic one loop tensor integrals within each computation. These are then decomposed into their own tensor basis with their associated scalar integrals. For instance, $$\begin{aligned}
\left. \int_k \frac{k_\mu k_\nu}{k^2 (k-p)^2 (k+q)^2} 
\right|_{p^2 \, = \, q^2 \, = \, - \mu^2} &=& \frac{4}{[d-2]} \left[
\eta_{\mu\nu} \left[ \frac{1}{4} I_1 + \frac{1}{3} I_2 + \frac{1}{6} I_3
+ \frac{1}{6} I_4 + \frac{1}{3} I_5 \right] \right. \nonumber \\
&& \left. 