Solution
= Solution
Expanding the integrand, the terms linear in $x$ integrate to zero. Therefore
$$
T_{ij}=\frac{4\pi a^4e^{-a^2}}3\delta_{ij}+4\pi a^2e^{-a^2}u_iv_j,
$$
so these are $\alpha$ and $\beta$.
= Solution
Expanding the integrand, the terms linear in $x$ integrate to zero. Therefore
$$
T_{ij}=\frac{4\pi a^4e^{-a^2}}3\delta_{ij}+4\pi a^2e^{-a^2}u_iv_j,
$$
so these are $\alpha$ and $\beta$.