Recent results from Pb-Au collisions at 158 GeV/c per nucleon obtained with the CERES spectrometer

During the 1996 lead run time, CERES has accumulated 42 million events, corresponding to a factor of 5 more statistics than in 1995 and 2.5 million events of a special photon-run. We report on the results of the low-mass e$^+$e$^-$-pair analysis. Since the most critical item is the poor signal-to-background ratio we also discuss the understanding of this background, in absolute terms, with the help of a detailed Monte Carlo simulation. We show preliminary results of the photon analysis and summarize the results of the hadron analysis preliminarily reported on already at QM'97Comment: 10 pages, 9 figures, Proceedings of the XIV Int. Conf. on Nucleus-Nucleus Collisions,Quark Matter 99, Torino, Italy, May 10 - 15, 199

Low-mass e+e- pair production in 158 A GeV Pb-Au collisions at the CERN SPS, its dependence on multiplicity and transverse momentum

We report a measurement of low-mass electron pairs observed in 158 GeV/nucleon Pb-Au collisions. The pair yield integrated over the range of invariant masses 0.2 < m < 2.0 GeV is enhanced by a factor of 3.5 +/- 0.4 (stat) +/- 0.9 (syst) over the expectation from neutral meson decays. As observed previously in S-Au collisions, the enhancement is most pronounced in the invariant-mass region 300-700 MeV. For Pb-Au we find evidence for a strong increase of the enhancement with centrality. In addition, we show that the enhancement covers a wide range in transverse momentum, but is largest at the lowest observed pt.Comment: 17 pages, 4 figures, submitted to Phys.Lett.

Is the analysis of flow at the CERN SPS reliable?

Several heavy ion experiments at SPS have measured azimuthal distributions of particles with respect to the reaction plane. These distributions are deduced from two-particle azimuthal correlations under the assumption that they result solely from correlations with the reaction plane. In this paper, we investigate other sources of azimuthal correlations: transverse momentum conservation, which produces back-to-back correlations, resonance decays, HBT correlations and final state interactions. These correlations increase with impact parameter: most of them vary with the multiplicity N like 1/N. When they are taken into account, the experimental results of the NA49 collaboration at SPS are significantly modified. These correlations might also explain an important fraction of the pion directed flow observed by WA98. Data should be reanalyzed taking into account carefully these non--flow correlations.Comment: Revised version (minor corrections), 13 pages, LaTeX, 6 Postscript figures included. Submitted to Physical Review

A doublet of 3" cylindrical silicon drift detectors in the CERES/NA45 experiment

We report on the performance of a doublet of 3" cylindrical silicon drift detectors installed as an upgrade of the CERES/NA45 electron pair spectrometer for the Pb-beam at the CERN SPS. The silicon detectors provide external particle tracking and background rejection of conversions and close Dalitz pairs. Results on vertex reconstruction and rejection from Pb test-run in 1994 are presented

Centrality and sNNDependenceofthe\sqrt{s_{NN}} Dependence of the dE_{T}/d\etaand and dN_{ch}/d\eta$ in Heavy Ion Collisions at Mid-Rapidity

The PHENIX experiment at RHIC has measured transverse energy and charged particle multiplicity at mid-rapidity in Au + Au collisions at $\sqrt{s_{NN}}$ = 19.6, 130, 62.4 and 200 GeV as a function of centrality. The presented results are compared to measurements from other RHIC experiments, and experiments at lower energies. The $\sqrt{s_{NN}}$ dependence of $dE_{T}/d\eta$ and $dN_{ch}/d\eta$ per pair of participants is consistent with logarithmic scaling for the most central events. The centrality dependence of $dE_{T}/d\eta$ and $dN_{ch}/d\eta$ is similar at all measured incident energies. At RHIC energies the ratio of transverse energy per charged particle was found independent of centrality and growing slowly with $\sqrt{s_{NN}}$. A survey of comparisons between the data and available theoretical models is also presented.Comment: Proccedings of the Workshop: Focus on Multiplcity at Bari, Italy, June 17-19,2004. To be submitted to the Jornal of Physics, "Conference series". Includes: 20 Pages, 15 figures, 3 Tables, 80 Referencie

Recombinant human soluble tumor necrosis factor receptor fusion protein as treatment for steroid refractory graft-versus-host disease following allogeneic hematopoietic stem cell transplantation

Etanercept is a recombinant human soluble tumor necrosis factor (TNF-γ) receptor fusion protein that inhibits TNF-γ, a major mediator in the pathogenesis of gratt-versus-host disease (GVHD). The purpose of our study was to evaluate the safety and efficacy of etanercept therapy in 21 patients with steroid-refractory acute GVHD (aGVHD) (n = 13) and chronic GVHD (cGVHD) (n = 8). Etanercept 25 mg was given subcutaneously twice weekly for 4 weeks followed by 25 mg weekly for 4 weeks. At the time of initiation of etanercept, 14 patients had skin, 13 had gastro-intestinal, 5 had liver, 5 had pulmonary, and 4 had oral involvement. Twelve patients (57%) completed 12 doses of therapy. Overall, 11 of 21 patients (52%) responded to the treatment with etanercept, including 6 patients (46%) with aGVHD [n = 4 complete response (CR), n = 2 partial response (PR)] and 5 patients (62%) with cGVHD (n = 1 CR, n = 4 PR). Clinical responses were most commonly seen in patients with refractory gut aGVHD with 55% of the patients having a CR and 9% having a PR. CMV reactivation occurred in 48% of patients, bacterial infections in 14% of patients, and fungal infections in 19% of patients. Fourteen patients (67%) were alive after a median follow-up of 429 days (range 71-1007 days) since initiation of etanercept. Seven patients died, 3 of infections, 2 of refractory aGVHD, and 2 of disease progression. In conclusion, our preliminary data indicate that etanercept is well tolerated and can induce a high response rate in patients with steroid-refractory aGVHD and cGVHD, particularly in the setting of Gl involvement. © 2006 Wiley-Liss, Inc