  The Standard Model (SM), as the quantum field theory of the strong and
electroweak interactions, needs be carried into curved spacetime to incorporate
gravity. This is done here not for the full but for the effective SM action by
integrating-in affine curvature. This approach leads to naturalization of the
SM Higgs sector and reduction of the cosmological constant down to the neutrino
scale thanks to the fact that quadratic (quartic) UV contributions to the Higgs
boson mass (vacuum energy) turn into the Higgs-curvature coupling (the
Einstein-Hilbert term). New physics beyond the SM, necessary for inducing
gravity properly, does not have to interact with the SM. It can form a secluded
sector to source non-interacting dark matter observable via only gravity, or a
weakly-coupled sector to source dark matter and possible collider signals.
