6 research outputs found

    System size and centrality dependence of the balance function in A + A collisions at sqrt s NN = 17.2 GeV

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    Electric charge correlations were studied for p+p, C+C, Si+Si and centrality selected Pb+Pb collisions at sqrt s_NN = 17.2$ GeV with the NA49 large acceptance detector at the CERN-SPS. In particular, long range pseudo-rapidity correlations of oppositely charged particles were measured using the Balance Function method. The width of the Balance Function decreases with increasing system size and centrality of the reactions. This decrease could be related to an increasing delay of hadronization in central Pb+Pb collisions

    Two-particle correlations in azimuthal angle and pseudorapidity in inelastic p + p interactions at the CERN Super Proton Synchrotron

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    Results on two-particle ΔηΔϕ correlations in inelastic p + p interactions at 20, 31, 40, 80, and 158 GeV/c are presented. The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN Super Proton Synchrotron. The data show structures which can be attributed mainly to effects of resonance decays, momentum conservation, and quantum statistics. The results are compared with the Epos and UrQMD models.ISSN:1434-6044ISSN:1434-605

    Recent results on (anti)nucleus and (anti)hyperon production in nucleus-nucleus collisions at CERN SPS energies

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    The NA49 experiment has collected comprehensive data on particle production in nucleus-nucleus collisions over the whole SPS beam energies range, the critical energy domain where the expected phase transition to a deconfined phase is expected to occur. The latest results from Pb+Pb collisions between 20AA GeV and 158AA GeV on baryon stopping and light nuclei production as well as those for strange hyperons are presented. The measured data on pp, pˉ\bar{p}, Λ\Lambda, Λˉ\bar{\Lambda}, Ξ\Xi^- and Ξˉ+\bar{\Xi}^+ production were used to evaluate the rapidity distributions of net-baryons at SPS energies and to compare with the results from the AGS and the RHIC for central Pb+Pb (Au+Au) collisions. The dependence of the yield ratios and the inverse slope parameter of the mtm_t spectra on the collision energy and centrality, and the mass number of the produced nuclei 3He^3He, tt, dd and dˉ\bar{d} are discussed within coalescence and statistical approaches. Analysis of the total multiplicity exhibits remarkable agreement between the measured yield for 3He^3He and those predicted by the statistical hadronization model. In addition, new results on Λ\Lambda and Λˉ\bar{\Lambda} as well as Ξ\Xi^- production in minimum bias Pb+Pb reactions at 40AA GeV and 158AA GeV and central C+C, Si+Si and Pb+Pb collisions are presented. The system size dependence of the yields of these hyperons was analysed to determine the evolution of strangeness enhancement relative to elementary p+p collisions.The NA49 experiment has collected comprehensive data on particle production in nucleus-nucleus collisions over the whole SPS beam energies range, the critical energy domain where the expected phase transition to a deconfined phase is expected to occur. The latest results from Pb+Pb collisions between 20AA GeV and 158AA GeV on baryon stopping and light nuclei production as well as those for strange hyperons are presented. The measured data on pp, pˉ\bar{p}, Λ\Lambda, Λˉ\bar{\Lambda}, Ξ\Xi^- and Ξˉ+\bar{\Xi}^+ production were used to evaluate the rapidity distributions of net-baryons at SPS energies and to compare with the results from the AGS and the RHIC for central Pb+Pb (Au+Au) collisions. The dependence of the yield ratios and the inverse slope parameter of the mtm_t spectra on the collision energy and centrality, and the mass number of the produced nuclei 3He^3He, tt, dd and dˉ\bar{d} are discussed within coalescence and statistical approaches. Analysis of the total multiplicity exhibits remarkable agreement between the measured yield for 3He^3He and those predicted by the statistical hadronization model. In addition, new results on Λ\Lambda and Λˉ\bar{\Lambda} as well as Ξ\Xi^- production in minimum bias Pb+Pb reactions at 40AA GeV and 158AA GeV and central C+C, Si+Si and Pb+Pb collisions are presented. The system size dependence of the yields of these hyperons was analysed to determine the evolution of strangeness enhancement relative to elementary p+p collisions

    Energy dependence of Lambda and anti-Lambda production at CERN-SPS energies

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    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

    Erratum to: Measurements of Ξ− and Ξ ¯+ production in proton–proton interactions at √sN N = 17.3 GeV in the NA61/SHINE experiment

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    his Erratum replaces incorrect plots shown in Fig. 7 with the corrected ones. In the publication, the NA57 [1] ratios of Ξ− and Ξ¯¯¯¯+ to the number of wounded nucleons at ⟨NW⟩=349 by mistake were plotted at the wrong values. The ratios were calculated and plotted by mistake using ⟨NW⟩=249. The correct normalization does not change the conclusions of the paper. The correctly normalized results are presented in Fig. 7
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