a\delta_{\{\mu\nu\rho\sigma00ij\}}
(\delta_{ij}J_{42}+{\vec{q}}_i{\vec{q}}_jJ_{43})
\nonumber\\&
+\delta\delta\delta\delta_{\{\mu\nu\rho\sigma0ijk\}}
(\delta{\vec{q}}_{\{ijk\}}J_{44}+{\vec{q}}_i{\vec{q}}_j{\vec{q}}_kJ_{45})
\nonumber\\&
+\delta_{\mu i}\delta_{\nu j}\delta_{\rho k}\delta_{\sigma l}
(\delta\delta_{\{ijkl\}}J_{46}
+\delta{\vec{q}}{\vec{q}}_{\{ijkl\}}J_{47}
\nonumber\\&
+{\vec{q}}_i{\vec{q}}_j{\vec{q}}_k{\vec{q}}_lJ_{48})\,. \nonumber\end{aligned}$$ All coefficients $J_{10}$, $J_{11}$, etc. have been written explicitly as functions of $I$, $J$, $K$, which can be integrated numerically, and the other simpler functions. The following definitions have been employed: $$\begin{aligned}
\delta{\vec{q}}_{\{ijk\}}=&\,
\delta_{ij}{\vec{q}}_k
+\delta_{ik}{\vec{q}}_j
+\delta_{jk}{\vec{q}}_i\,,
\\
\delta{\vec{q}}{\vec{q}}_{\{ijkl\}}=&\,
\delta_{ij}{\vec{q}}_k{\vec{q}}_l
+\delta_{ik}{\vec{q}}_j{\vec{q}}_l
+\delta_{il}{\vec{q}}_j{\vec{q}}_k \nonumber\\
&
+\delta_{jk}{\vec{q}}_i{\vec{q}}_l
+\delta_{jl}{\vec{q}}_i{\vec{q}}_k
+\delta_{kl}{\vec{q}}_i{\vec{q}}_j\,,
\\
\delta\delta_{\{ijkl\}}=&\,
\delta_{ij}\delta_{kl}
+\delta_{ik}\delta_{jl}
+\delta_{il}\delta_{jk}\,.\end{aligned}$$ The other quantities, $\delta\delta\delta_{\{\mu\nu\rho00i\}}$, $\delta\delta\delta_{\{\mu\nu\rho0ij\}}$, etc, are not meant to be contracted with the indexes $i$, $j$, and $k$ appearing in the rest of the expressions. They only indicate how many of the indexes $\mu$, $\nu$, $\rho$, and $\sigma$ must be temporal and how many spatial. It does not matter the order in which $0$, $i$, $j$, and $k$ are assigned to $\mu$, $\nu$, $\rho$, and $\sigma$, since all the integrals $J_{\mu\nu}$, $J_{\mu\nu\rho}$, etc, are symmetric with respect to these indexes. For example $$J_{00i}=J_{0i0}=J_{i00}={\vec{q}}_i J_{31} \,.$$

Results for the master integrals
--------------------------------

We have regularized the master integrals via dimensional regularization, where the integrals depend on the momentum dimension $D_\eta$, or more specifically, on the p