  Halo/Cluster Effective Field Theory describes halo/cluster nuclei in an
expansion in the small ratio of the size of the core(s) to the size of the
system. Even in the point-particle limit, neutron halo nuclei have a finite
charge radius, because their center of mass does not coincide with their center
of charge. This point-particle contribution decreases as $1/A_c$, where $A_c$
is the mass number of the core, and diminishes in importance compared to other
effects, e.g., the size of the core to which the neutrons are bound. Here we
propose that for heavy cores the EFT expansion should account for the small
factors of $1/A_c$. As a specific example, we discuss the implications of this
organizational scheme for the inclusion of finite-size effects in expressions
for the charge radii of halo nuclei. We show in particular that a short-range
operator could be the dominant effect in the charge radius of one-neutron halos
bound by a P-wave interaction. The point-particle contribution remains the
leading piece of the charge radius for one-proton halos, and so Halo EFT has
more predictive power in that case.
