Abstract

Using quantum Monte Carlo Methods, we compute the differential cross sections for elastic scattering of dark matter (DM) particles off light nuclei, up to $A=6$ (d, $^3$H, $^3$He, $^4$He, and $^6$Li). DM-nucleon one- and two-body currents are obtained to next-to-leading order in chiral effective theory, and they are derived from a DM-quark and DM-gluon effective interaction. The nuclear ground states wave functions are obtained from a phenomenological nuclear Hamiltonian, composed of the Argonne $v_{18}$ two-body interaction and the three-body Urbana IX. In this framework, we study the impact of one- and two-body currents and discuss the size of nuclear uncertainties. This work evaluates for the first time two-body effects in $A=4,6$ systems and provides the nuclear structure input that can be used to assess the sensitivity of future experimental searches of (light) dark matter, especially relevant for possible experimental targets such as $^3$He and $^4$He.