We present a precise measurement of double-polarization asymmetries in the $^3vec{mathrm{He}}(vec{mathrm{e}},mathrm{e}mathrm{d})$ reaction. This particular process is a uniquely sensitive probe of hadron dynamics in $^3mathrm{He}$ and the structure o
f the underlying electromagnetic currents. The measurements have been performed in and around quasi-elastic kinematics at $Q^2 = 0.25,(mathrm{GeV}/c)^2$ for missing momenta up to $270,mathrm{MeV}/c$. The asymmetries are in fair agreement with the state-of-the-art calculations in terms of their functional dependencies on $p_mathrm{m}$ and $omega$, but are systematically offset. Beyond the region of the quasi-elastic peak, the discrepancies become even more pronounced. Thus, our measurements have been able to reveal deficiencies in the most sophisticated calculations of the three-body nuclear system, and indicate that further refinement in the treatment of their two- and/or three-body dynamics is required.
