φ-Meson Mass Modification in Heavy-Ion Collisions

We recently presented a method of analyzing invariant-mass spectra of kaon pairs resulting from decay of φ mesons produced in high-energy heavy-ion collisions. It can be used to extract the shifts in the mass and the width (∆M and ∆Γ) of the φ 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 ∆M is significantly larger than that obtained with an earlier method. Our results are consistent with the experimentally observed pT dependence of the mass shift.