Centrality and Energy Dependence of Proton, Light Fragment and Hyperon Production

Recent results of the NA49 collaboration are discussed. These include the energy dependence of stopping and the production of the light fragments t and 3He. New data on the system size dependence of hyperon production at 40A and 158AGeV are also presented.Comment: 4 pages, Quark Matter 2006 proceeding

Niemieckie szkolnictwo wyższe - struktura, wybrane problemy i kierunki zmian

This article presents the structure of higher education in Germany, its selected problems and ongoing changes. The debate on higher education in Germany has become more heated in recent years following the uniting of Germany. For more than forty years Germany had two different educational systems. When the country united in 1990 it was necessary to adjust the educational system of the ex-GDR to the Solutions accepted in West Germany. Also, within the last few years the so-called Europaische Dimension in Hochschulbereich has also gained importance. It is now necessary to adjust university and college structure and syllabuses to the obligatory demands of the European Union. Accreditation procedures enforcing changes in the quality of education were introduced in German higher education in 1998. Methods of management in higher education are also changing. Many of these changes are positive but several problems, e.g., problems concerning the compatibility between the structure and contents of higher education and the demands of the labour market, competition and the increasing autonomy of the universities, have also emerged. To what extent has the catchword “diversity and competition” proclaimed by the German educational authorities found support in the structure and syllabuses of the universities? This is one of the questions the author of this article is trying to answer.W artykule przedstawiono strukturę, wybrane problemy oraz zmiany zachodzące w ostatnich latach w niemieckim szkolnictwie wyższym. Dyskusje dotyczące szkolnictwa wyższego w Niemczech zaostrzyły się w ostatnich latach. Przyczyniło się do tego zjednoczenie Niemiec. W kraju, w którym przez ponad czterdzieści lat funkcjonowały dwa odmienne systemy szkolne, od roku 1990 ważnym zadaniem stało się przystosowanie szkolnictwa byłej NRD do rozwiązań zachodnioniemieckich. W ostatnich latach równie ważna stała się tzw. perspektywa europejska (europaische Dimension im Hochschulbereich), wymagająca przystosowania struktury i programów szkół wyższych do wymagań obowiązujących w Unii Europejskiej. Od roku 1998 wprowadzono w szkolnictwie wyższym Niemiec procedury akredytacyjne, wymuszające zmiany w jakości kształcenia. Zmianie ulegają również sposoby zarządzania szkolnictwem wyższym. Oprócz pozytywnych przemian ujawniają się także problemy dotyczące powiązania struktury szkolnictwa wyższego i treści kształcenia z wymaganiami rynku pracy, powstawania konkurencji oraz wzrostu autonomii szkół wyższych. Jak dalece hasło „zróżnicowanie i konkurencja” , głoszone przez niemieckie władze oświatowe, znajduje potwierdzenie w strukturze i programach szkół wyższych, to jedno z głównych pytań, na które stara się znaleźć odpowiedź autorka artykułu

Xi- and Xi+ production in Pb + Pb collisions at 40 A GeV at CERN SPS

First results on the production of Xi- and Anti-xi hyperons in Pb+Pb interactions at 40 A GeV are presented. The Anti-xi/Xi- ratio at midrapidity is studied as a function of collision centrality. The ratio shows no significant centrality dependence within statistical errors; it ranges from 0.07 to 0.15. The Anti-xi/Xi- ratio for central Pb+Pb collisions increases strongly with the collision energy

Energy Dependence of Particle Production in nucleus-nucleus collisions at the CERN SPS

New preliminary results on kaon and pion production in central 30AGeV Pb+Pb collisions are presented. The data are compared to data at lower and higher energies to examine the energy dependence of the kaon to pion ratios and the inverse slope parameters of kaons. The results are compared to expectations from models with and without a phase transition to the Quark Gluon Plasma.Comment: 4 pages, 5 figures, presented at XXXVIIIth Rencontres de Moriond, QCD and High Energy Hadronic Interactions sessio

Nuclear modification at sqrt{s_{NN}}=17.3 GeV, measured at NA49

Transverse momentum spectra up to 4.5 GeV/c were measured around midrapidity in Pb+Pb reactions at sqrt{s_{NN}}=17.3 GeV, for pi^{+/-}, p, pbar and K^{+/-}, by the NA49 experiment. The nuclear modification factors R_{AA}, R_{AA/pA} and R_{CP} were extracted and are compared to RHIC results at sqrt{s_{NN}}=200 GeV. The modification factor R_{AA} shows a rapid increase with transverse momentum in the covered region. The modification factor R_{CP} shows saturation well below unity in the pi^{+/-} channel. The extracted R_{CP} values follow the 200 GeV RHIC results closely in the available transverse momentum range for all particle species. For pi^{+/-} above 2.5 GeV/c transverse momentum, the measured suppression is smaller than that observed at RHIC. The nuclear modification factor R_{AA/pA} for pi^{+/-} stays well below unity.Comment: Proceedings of Quark Matter 2008 conferenc

Xi and AntiXi production in Pb+Pb collisions at 40 AGeV at CERN SPS

First results on the production of Xi and AntiXi hyperons in Pb+Pb interactions at 40 AGeV are presented. The AntiXi/Xi ratio at midrapidity is studied as a function of collision centrality. The ratio shows no significant centrality dependence within statistical errors; it ranges from 0.07 to 0.15. The AntiXi/Xi ratio for central Pb+Pb collisions increases strongly with the collision energy.Comment: 6 pages, 6 figures, proceedings of SQM03, to be published in Journal of Physics G; V2: changes in table 1 and figure

Anti-nuclei and nuclei production in Pb+Pb collisions at CERN SPS energies

We present new results on production of 3He and t obtained by the NA49 experiment in 20A, 30A, 40A and 80A GeV central Pb+Pb collisions at the CERN SPS. Transverse mass spectra and rapidity distributions for clusters measured over a large phase space domain are discussed. We observe a weak dependence of the mid-rapidity t/3He ratio on collision energy at SPS. The energy dependence of the total yield for 3He is remarkably reproduced by a statistical hadron gas model. A gradual decrease of the coalescence parameter B3 for 3He with $\sqrt {s_{NN}}$ is observed.In addition, a measurement of the yield of anti-deuterons in Pb+Pb reactions at SPS's top energy of $\sqrt {s_{NN}}$ = 17.2 GeV is presented.Comment: 4 pages, 8 figures. Talk at HEP07, Manchester, July 19-25, 2007; submitted to Journal of Physics: Conference Serie

Energy dependence of hadronic observables in central Pb+Pb reactions at the CERN SPS

In the recent years the NA49 experiment has collected data on Pb+Pb collisions at beam energies between 20 to 158 AGeV with the objective to cover the critical region of energy densities where the expected phase transition to a deconfined phase might occur in the early stage of the reactions. In this contribution the energy dependence of various hadronic observables is presented. These include m_t- and rapidity- distributions, particle ratio fluctuations, as well as HBT radii.Comment: 7 pages, 5 figures, Proceedings of the 20th Winter Workshop on Nuclear Dynamics, Jamaic

Energy Dependence of Λ and ¯Λ Production at CERN-SPS Energies

Rapidity distributions for $\Lambda$ and $\bar{\Lambda}$ hyperons in central Pb-Pb collisions at 40, 80 and 158 A$\cdot$GeV and for ${\rm K}_{s}^{0}$ mesons at 158 A$\cdot$GeV 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 $\bar{\Lambda}/\pi$ is observed. The $\bar{\Lambda}/\Lambda$ ratio shows a steep increase with collision energy. Evidence for a $\bar{\Lambda}/\bar{\rm p}$ ratio greater than 1 is found at 40 A$\cdot$GeV

High p_T Spectra of Identified Particles Produced in Pb+Pb Collisions at 158GeV/nucleon Beam Energy

Transverse momentum spectra of pi^{+/-}, p, pbar, K^{+/-}, K^0_s and Lambda at midrapidity were measured at high p_T in Pb+Pb collisions at 158GeV/nucleon beam energy by the NA49 experiment. Particle yield ratios (p/pi, K/pi and Lambda/K^0_s) show an enhancement of the baryon/meson ratio for p_T>2GeV/c. The nuclear modification factor R_{CP} is extracted and compared to RHIC measurements and pQCD calculations.Comment: Quark Matter 2005 parallel section proceeding