Production of ϱ + ω and Φ in p-W and SU collisions at 200 GeV/nucleon

The transverse mass differential cross-sections for the ϱ + ω and Φ resonances is obtained, in the central rapidity region, in p-W and SU interactions at 200 GeV/nucleon. The measured ϱ + ω and Φ temperatures are ∼ 15% higher in SU as compared to p-W collisions. The ratio of cross-sections times branching ratios into the dimuon channel BΦσΦ(Bϱσϱ + Bωσω) is studied as a function of the energy density reached in the collision and of the dimuon transverse momentum. The measured ratio is 2 to 3 times larger in SU than in p-W collisions and an enhancement is observed in SU interactions with increasing energy density.