  We study deuteron production using no-coalescence hydrodynamic + transport
simulations of central AuAu collisions at $\sqrt{s_{NN}} = 7 - 200$ GeV.
Deuterons are sampled thermally at the transition from hydrodynamics to
transport, and interact in transport dominantly via $\pi p n \leftrightarrow
\pi d$ reactions. The measured proton, Lambda, and deuteron transverse momentum
spectra and yields are reproduced well for all collision energies considered.
We further provide a possible explanation for the measured minimum in the
energy dependence of the coalescence parameter, $B_2(\sqrt{s_{NN}})$ as well as
for the difference between $B_2(d)$ for deuterons and that for anti-deuterons,
$B_2(\bar{d})$.
