  We show that if the connected sum of two knots with coprime Alexander
polynomials is doubly slice, then the Ozsv\'ath-Szab\'o correction terms as
smooth double sliceness obstructions vanish for both knots. Recently, Jeffrey
Meier gave smoothly slice knots that are topologically doubly slice, but not
smoothly doubly slice. As an application, we give a new example of such knots
that is distinct from Meier's knots modulo doubly slice knots.
