Charmonia production in 450-GeV/c proton induced reactions.

The NA38 collaboration Abreu, M.C. ; Baglin, C. ; Baldit, A. ; et al.
Phys.Lett.B 444 (1998) 516-522, 1998.
Inspire Record 478387 DOI 10.17182/hepdata.49294

Absolute J/ ψ and ψ ′ production cross sections have been measured at the CERN SPS, with 450 GeV/ c protons incident on a set of C, Al, Cu and W targets. Complementing these values with the results obtained by experiment NA51, which used the same beam and detector with H and D targets, we establish a coherent picture of charmonia production in proton-induced reactions at SPS energies. In particular, we show that the scaling of the J/ ψ cross section with the mass number of the target, A, is well described as A α , with α ψ =0.919±0.015. The ratio between the J/ ψ and ψ ′ yields, in our kinematical window, is found to be independent of A, with α ψ ′ − α ψ =0.014±0.011.

5 data tables

The ratio of the production cross sections, in the di-muon channel. Note that there are wo set of CU and WT data with targets of different lengths. An average values is also given for these.

The J/PSI absolute cross sections, times the BR to di-muons.

The PSI(3685) absolute cross sections, times the BR to di-muons.

More…

Muon pair and vector meson cross-sections in p W and S U collisions at 200-GeV/nucleon

The NA38 collaboration Abreu, M.C. ; Baglin, C. ; Baldisseri, A. ; et al.
Phys.Lett.B 368 (1996) 230-238, 1996.
Inspire Record 428066 DOI 10.17182/hepdata.28422

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.

4 data tables

Statistical errors only.

Statistical errors only.

Statistical errors only.

More…

psi-Prime and J / psi production in p W, p U and S U interactions at 200-GeV/nucleon

The NA38 collaboration Baglin, C. ; Bussière, A. ; Guillaud, J.P. ; et al.
Phys.Lett.B 345 (1995) 617-621, 1995.
Inspire Record 387018 DOI 10.17182/hepdata.36562

Ψ′ and J/Ψ yields are compared in p-W, p-U and S-U interactions at 200 GeV/nucleon. Their ratio decreases from proton-t to sulphur-induced reactions. It also decreases in sulphur-induced reactions from peripheral to central collisions. This result could indicate that the Ψ′ and J/Ψ suppression mechanisms have different origins in p- and S-induced reactions.

3 data tables

No description provided.

No description provided.

No description provided.


J / psi, psi-prime and muon pair production in p - W and S - U collisions

The NA38 collaboration Abreu, M.C. ; Baglin, C. ; Baldit, A. ; et al.
Nucl.Phys.A 566 (1994) 77C-85C, 1994.
Inspire Record 358346 DOI 10.17182/hepdata.36538

In this paper we present a study on the production of the J ψ and ψ′ resonances, decaying into muon pairs, in S-U collisions, at 200 GeV per incident nucleon. We find that the ratio between ψ′ and tJ ψ yields decreases as E T , the neutral transverse energy produced in the collision, increases. There is also a clear decrease of this ratio when going from p-W to S-U interactions. Assuming the high mass continuum to be Drell-Yan we discuss the possible understanding of the intermediate dimuon mass region as a superposition of Drell-Yan (extrapolated down in mass) and muon pairs from the semileptonic decays of charmed mesons. The p-W data is found to be explained by this procedure. However, the S-U data seems to be incompatible with a linear extrapolation from the proton-nucleus results.

4 data tables

THE NEUTRAL TRANSVERSE ENERGY PRODUCED IN THE COLLISION > 15 GEV.

THE NEUTRAL TRANSVERSE ENERGY PRODUCED IN THE COLLISION > 15 GEV.

THE NEUTRAL TRANSVERSE ENERGY PRODUCED IN THE COLLISION > 15 GEV.

More…