  We study the collision energy dependence of (anti-)deuteron and (anti-)triton
production in the most central Au+Au collisions at $\sqrt{s_\mathrm{NN}}=$ 7.7,
11.5, 19.6, 27, 39, 62.4 and 200 GeV, using the nucleon coalescence model. The
needed phase-space distribution of nucleons at the kinetic freeze-out is
generated from a new 3D hybrid dynamical model (\texttt{iEBE-MUSIC}) by using a
smooth crossover equation of state (EoS) without a QCD critical point. Our
model calculations predict that the coalescence parameters of (anti-)deuteron
($B_2(d)$ and $B_2(\bar{d})$) decrease monotonically as the collision energy
increases, and the light nuclei yield ratio $N_t N_p/N_d^2$ remains
approximately a constant with respect to the collision energy. These calculated
observables fail to reproduce the non-monotonic behavior of the corresponding
data from the STAR Collaboration. Without including any effects of the critical
point in our model, our results serve as the baseline predictions for the
yields of light nuclei in the search for the possible QCD critical points from
the experimental beam energy scan of heavy ion collisions.
