The NA60 experiment at the CERN SPS has studied $phi$ meson production in In-In collisions at 158A GeV via both the $K^+K^-$ and the $mu^+mu^-$ decay channels. The yields and inverse slope parameters of the $m_T$ spectra observed in the two channels are compatible within errors, different from the large discrepancies seen in Pb-Pb collisions between the hadronic (NA49) and dimuon (NA50) decay channels. Possible physics implications are discussed.
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