  The nucleon coalescence model is one of the most popular theoretical models
for light nuclei production in high-energy heavy-ion collisions. The production
of light nuclei $d$, $t$, $^{3}$He, and $^{4}$He is studied using the transport
model JAM with a simplified afterburner coalescence at $\sqrt{s_{NN}}=3$ GeV
Au+Au collisions. We scan the cut-off of phenomenological coalescence
parameters, the relative spatial distance $\Delta R$ and momentum difference
$\Delta P$, for formation of light nuclei by nucleon coalescence to reproduce
the light nuclei $p_{\rm T}$ spectra measured by STAR experiment. The results
indicate a potential connection between the coalescence parameters and the
binding energy as well as the diameter of these light nuclei.
