Ab-initio calculation of the proton and the neutron's scalar couplings for new physics searches

Understand

Many low-energy, particle-physics experiments seek to reveal new fundamental physics by searching for very rare scattering events on atomic nuclei.

• The interpretation of their results requires quantifying the non-linear effects of the strong interaction on the spin-independent couplings of this new physics to protons and neutrons.
• Here we present a fully-controlled, ab-initio calculation of these couplings to the quarks within those constituents of nuclei.
• We use lattice quantum chromodynamics computations for the four lightest species of quarks and heavy-quark expansions for the remaining two.