  We recently presented a method of analyzing invariant-mass spectra of kaon
pairs resulting from decay of $\phi$ mesons produced in high-energy heavy-ion
collisions. It can be used to extract the shifts in the mass and the width
($\Delta M$ and $\Delta \Gamma$) of the $\phi$ mesons when they are inside the
dense matter formed in these collisions. We have now performed a Monte-Carlo
simulation of this process. We illustrate our method with the help of available
preliminary data. Extracted value of $\Delta M$ is significantly larger than
that obtained with an earlier method. Our results are consistent with the
experimentally observed $p_T$ dependence of the mass shift.
