Direct detection of fermionic and vector dark matter with polarised targets

We study the scattering of Milky Way dark matter (DM) particles by spin-polarised target nuclei within a set of simplified models for fermionic and vector DM where DM interacts with spin 1/2 point-like nuclei through the exchange of a vector or pseudo-vector mediator particle. This study is motivated by the possibility of using polarised targets to gain novel insights into the nature of DM. For fermionic DM, we provide an explicit expression for the polarised DM-nucleus scattering cross section refining previous results found in the literature. For vector DM, we calculate the polarised cross section for DM-nucleus scattering for the first time. We find that polarised targets can in principle be used to discriminate fermionic from vector DM.