Rescattering of Vector Meson Daughters in High Energy Heavy Ion Collisions

We consider the role of hadronic rescattering of daughter kaons on the observed mass spectra from $\phi$ meson decays in ultra-relativistic heavy ion collisions. A hadronic cascade code (RQMD v2.4) shows that $\sim$17% of all $\phi$'s decaying to $K^+K^-$ have a rescattered daughter. This significantly affects the reconstructed invariant mass of the pair and shifts the reconstructed $\phi$ mesons out of the mass peak. Kaon rescattering depletes the low $m_t$ region, changing the observed $m_t$ distribution relative to the dilepton channel, an apparent change in the experimentally determined branching ratio not necessarily related to chiral symmetry restoration.