  We derive the formulas for calculating the squeezed back-to-back correlation
(SBBC) between a boson and antiboson with nonzero width produced in
relativistic heavy-ion collisions. The SBBCs of $D^0$ and $\phi$ mesons with
finite in-medium widths are studied. We find that the finite width can change
the pattern of the SBBC function of $D^0{\bar D}^0$ with respect to mass.
However, the SBBC function of $\phi\phi$ is insensitive to the width. In the
high-particle-momentum region, the SBBC function of $\phi\phi$ increases with
particle momentum rapidly and can exceed that of $D^0{\bar D}^0$ whether the
width is nonzero or not.
