Muon pair production is studied in p - W and S U collisions at 200 GeV per nucleon, as a function of transverse momentum P Tμμ . The inclusive ϱ + ω and Φ differential cross-sections dσ dP T are measured in the dimuon decay channel, for P T ≥ 0.6 GeV/c, in the central rapidity region, 3.0≤ y ≤ 4.0. Assuming the power law A-dependence σ = σ 0 ( A beam · A target ) α , the study of the integrated cross-sections for p - W and S U collisions leads to α ϱ + ω = 1.00±0.02±0.07 and α Φ = 1.23±0.03±0.05, showing clear evidence of Φ enhancement in S U interactions as compared to p - W collisions.
Statistical errors only.
Statistical errors only.
Statistical errors only.
The focus of this experiment is on dimuons at low M T but the mass range up to the J ψ is also covered. Dimuons are measured over a wide rapidity interval, ranging from nearly central to very forward rapidities. Experimental results concerning the vector meson production in p-W and S-W interactions at 200 GeV/c/A as a function of the charged multiplicity are presented together with a comparison of the observed invariant mass spectra with the dimuon conventional sources in the mass region between the φ and J ψ mesons. The observed large difference in the shape and absolute value of p-W and S-W dimuon spectra cannot be explained in terms of a direct extrapolation of the p-p results.
No description provided.
No description provided.
The focus of this experiment is on dimuons at low M T but the mass range up to the J ψ is also covered. Dimuons are measured over a wide rapidity interval, ranging from nearly central to very forward rapidities. We present the experimental results in different kinematic regions and as a function of charged multiplicity. The observed dimuon spectra are also compared to conventional sources of lepton pairs production.
No description provided.
No description provided.
No description provided.
We present our first results on φ and ϱ+ω production in pW and SW collisions at 200 GeV/nucleon, obtained using the HELIOS/3 muon spectrometer, which measures dimuons in a large acceptance in transverse momentum and rapidity. The data show a clear increase of the ratio φ/(ϱ+ω) going from pW to SW collisions and a slight increase from peripheral to central SW collisions. This the case for low (p t ≤ 0.6GeV/c) and high (p t > 0.6 GeV/c) transverse momentum. The rise is due to an increase in the number of produced φ mesons.
No description provided.
No description provided.