Year of publication
- Indications for the onset of deconfinement in nucleus nucleus collisions (2004)
- The hadronic final state of central Pb+Pb collisions at 20, 30, 40, 80, and 158 AGeV has been measured by the CERN NA49 collaboration. The mean transverse mass of pions and kaons at midrapidity stays nearly constant in this energy range, whereas at lower energies, at the AGS, a steep increase with beam energy was measured. Compared to p+p collisions as well as to model calculations, anomalies in the energy dependence of pion and kaon production at lower SPS energies are observed. These findings can be explained, assuming that the energy density reached in central A+A collisions at lower SPS energies is sufficient to transform the hot and dense nuclear matter into a deconfined phase.
- Upper limit of D 0 production in central Pb-Pb collisions at 158 A GeV (2005)
- Results are presented from a search for the decays D0 -> K min pi plus and D0 bar -> K plus pi min in a sample of 3.8x10^6 central Pb-Pb events collected with a beam energy of 158A GeV by NA49 at the CERN SPS. No signal is observed. An upper limit on D0 production is derived and compared to predictions from several models.
- Indications for the onset of deconfinement in Pb + Pb collisions at the CERN SPS from NA49 (2005)
- Particle production in central Pb+Pb collisions was studied with the NA49 large acceptance spectrometer at the CERN SPS at beam energies of 20, 30, 40, 80, and 158 GeV per nucleon. A change of the energy dependence is observed around 30A GeV for the yields of pions and strange particles as well as for the shapes of the transverse mass spectra. At present only a reaction scenario with onset of deconfinement is able to reproduce the measurements.
- Recent results from the NA49 experiment (2005)
- Recent results of the NA49 collaboration are presented. Transverse mass spectra as well as total multiplicities of identified particles are discussed. The study of their evolution from AGS over SPS to the highest RHIC energy reveals a couple of interesting features. These include a sudden change in the energy dependence of the mt-spectra and of the yields of strange hadrons around 30A GeV. Additionally, new results on particle production at high-pt for Pb+Pb collsions at 158A GeV, as well as on the v2 of L, are discussed.
- Energy dependence of Lambda and anti-Lambda production at CERN-SPS energies (2002)
- Rapidity distributions for Lambda and anti-Lambda hyperons in central Pb-Pb collisions at 40, 80 and 158 AGeV and for K 0 s mesons at 158 AGeV are presented. The lambda multiplicities are studied as a function of collision energy together with AGS and RHIC measurements and compared to model predictions. A different energy dependence of the Lambda/pi and anti-Lambda/pi is observed. The anti-Lambda/Lambda ratio shows a steep increase with collision energy. Evidence for a anti-Lambda/anti-p ratio greater than 1 is found at 40 AGeV.