  We develop a new way to analytically calculate loop integrals in the
Effective Field Theory of Large Scale-Structure. Previous available methods
show severe limitations beyond the one-loop power spectrum due to analytical
challenges and computational and memory costs. Our new method is based on
fitting the linear power spectrum with cosmology-independent functions that
resemble integer powers of quantum field theory massive propagators with
complex masses. A remarkable small number of them is sufficient to reach enough
accuracy. Similarly to former approaches, the cosmology dependence is encoded
in the coordinate vector of the expansion of the linear power spectrum in our
basis. We first produce cosmology-independent tensors where each entry is the
loop integral evaluated on a given combination of basis vectors. For each
cosmology, the evaluation of a loop integral amounts to contracting this tensor
with the coordinate vector of the linear power spectrum. The 3-dimensional loop
integrals for our basis functions can be evaluated using techniques familiar to
particle physics, such as recursion relations and Feynman parametrization. We
apply our formalism to evaluate the one-loop bispectrum of galaxies in redshift
space. The final analytical expressions are quite simple and can be evaluated
with little computational and memory cost. We show that the same expressions
resolve the integration of all one-loop $N$-point function in the EFTofLSS.
This method, which is originally presented here, has already been applied in
the first one-loop bispectrum analysis of the BOSS data to constraint
$\Lambda$CDM parameters and primordial non-Gaussianities, see arXiv:2206.08327
and arXiv:2201.11518.
