Quantum Monte Carlo calculations of dark matter scattering off light nuclei

Abstract

We compute the matrix elements for elastic scattering of dark matter (DM) particles off light nuclei (${}^2$H, ${}^3$H, ${}^3$He, ${}^4$He and ${}^6$Li) using quantum Monte Carlo methods. We focus on scalar-mediated DM-nucleus interactions and use scalar currents obtained to next-to-leading order in chiral effective theory. The nuclear ground states are obtained from a phenomenological nuclear Hamiltonian that includes the Argonne $v_{18}$ two-body interaction and the three-body Urbana IX interaction. Within this approach, we study the impact of one- and two-body currents and discuss the size of nuclear uncertainties, including for the first time two-body effects in $A=4$ and $A=6$ systems. Our results provide the nuclear structure input needed to assess the sensitivity of future experimental searches of (light) dark matter using light nuclei, such as ${}^3$He and ${}^4$He.

Comments: 9 pages, 6 figures