Recent results on spectra and yields from NA49

The energy dependence of hadron production in central Pb+Pb collisions is presented and discussed. In particular, midrapidity m_T-spectra for pi-, K-, K+, p, bar p, d, phi, Lambda and bar Lambda at 40, 80 and 158 AGeV are shown. In addition Xi and Omega spectra are available at 158 AGeV. The spectra allow to determine the thermal freeze-out temperature T and the transverse flow velocity beta_T at the three energies. We do not observe a significant energy dependence of these parameters; furthermore there is no indication of early thermal freeze-out of Xi and Omega at 158 AGeV. Rapidity spectra for pi-, K-, K+ and phi at 40, 80 and 158 AGeV are shown, as well as first results on Omega rapidity distributions at 158 AGeV. The chemical freeze-out parameters T and mu_B at the three energies are determined from the total yields. The parameters are close to the expected phase boundary in the SPS energy range and above. Using the total yields of kaons and lambdas, the energy dependence of the strangeness to pion ratio is discussed. A maximum in this ratio is found at 40 AGeV. This maximum could indicate the formation of deconfined matter at energies above 40 AGeV. A search for open charm in a large sample of 158 AGeV events is presented. No signal is observed. This result is compared to several model predictions

Industrialization and Intergenerational Mobility in Sweden

The relationship between industrialization and intergenerational mobility has been a topic of discussion for over forty years. In this article both total mobility and relative mobility chances are studied in the decades preceding industrialization and the decades during industrialization. A high-quality data set is used covering the male population of a region in the north of Sweden during the 19th century. Total intergenerational mobility increased during industrialization until, at the end of the century, both industrialization and the growth of mobility stagnated. Sectorial barriers resulted in unequal relative mobility chances before and also during industrialization. However, sons from self-employed classes were less likely to inherit the class position of their father after the onset of industrialization. At the same time, mobility between classes differing in status became less frequent. These results show a decline in the importance of the direct transfer of resources between generations and may indicate the increasing importance of education

Kaon and open charm production in central lead-lead collisions at the CERN SPS

This thesis describes the experimental study of hadronic systems with a very high energy density and temperature. From theoretical caluclations it is expected that hadronic matter undergoes a phase transition to a deconfined state at an energy density of about 1 GeV/fm^3 or a temperature of 170 MeV. The goal of the experiments is to observe the phase transition and study the properties of the deconfined state, the Quark Gluon Plasma (QGP). Two different measurements are described and the results are discussed. The first measurement concerns the momentum distributions and total yields of kaons in lead-lead collisions at 40, 80 and 158 AGeV beam energy. Kaons are the most abundant carrier of the relatively heavy strange quarks and their production is expected to be sensitive to the energy density and the state of matter early in the collision. The second measurement is a search for the production of mesons which carry the even heavier charm quark, at the highest beam energy. The measurements have been performed with the NA49 detector at the SPS accelerator at CERN. The main detector elements are four Time Projection Chambers (TPCs), which record the trajectories of a large fraction of the final state particles to determine the charge and the momentum of each particle. In addition, the measurement of the ionisation energy loss dE/dx in the TPCs allows to identify pions, kaons and protons. Additional detectors provide a measurement of the time-of-flight in a limited acceptance. Combining the time-of-flight and dE/dx measurements greatly improves the separation of the different particle species. The kaon momentum distributions as presented in this thesis have been determined using the dE/dx measurement in the TPCs. The time-of-flight information is used for a detailed study of the peak shape of the dE/dx measurement. The resulting kaon spectra and total yields provide strong indications that interactions between produced particles or even thermalisation play an important role in nucleus-nucleus collisions. The measured kaon yields are compared to two different models which are based on purely hadronic processes, not taking into account the possible phase transition to the QGP. The hadron-transport model RQMD takes into account collisions between produced particles, and the Hadron Gas Model assumes thermalisation. Both models are in reasonable agreement with the data. A model which does assume the phase transition, the Statistical Model of the Early Stage (SMES), shows even better agreement with the data. It predicts a sharp maximum in the strangeness to pion ratio between 10 AGeV, the highest beam energy of earlier experiments, and 40 AGeV, the lowest beam energy used in this thesis. The present data are consistent with this prediction, but future measurements at 20 and 30 AGeV will decide whether the sharp maximum is indeed observed. If indeed an equilibrium QGP is formed at the highest SPS energies, as is expected within the SMES, this would also lead to a relatively large production of charm quarks and hence open charm mesons. Therefore, a large sample of three million lead-lead events at 158 AGeV was taken to search for open charm production. No signal has been observed in the analysis, implying that the charm yield is lower than the expected yield in an equilibrium QGP. It is concluded that if a QGP is formed in the collisions, it does not live long enough or has too low a temperature to allow the charm production to reach equilibrium

Heavy-ion physics studies for the Future Circular Collider

The Future Circular Collider (FCC) design study is aimed at assessing the physics potential and the technical feasibility of a new collider with centre-of-mass energies, in the hadron-hadron collision mode including proton and nucleus beams, more than seven-times larger than the nominal LHC energies. An electron-positron collider in the same tunnel is also considered as an intermediate step, which would provide the electron-hadron option in the long term. First ideas on the physics opportunities with heavy ions at the FCC are presented, covering the physics of Quark-Gluon Plasma, gluon saturation, photon-induced collisions, as well as connections with ultra-high-energy cosmic rays.Comment: 4 pages, 3 figures, proceedings of Quark Matter 2014, Darmstadt, Germany, submitted to Nucl. Phys.

Strangeness dynamics in relativistic nucleus-nucleus collision

We investigate hadron production as well as transverse hadron spectra in nucleus-nucleus collisions from 2 A.GeV to 21.3 A.TeV within two independent transport approaches (UrQMD and HSD) that are based on quark, diquark, string and hadronic degrees of freedom. The comparison to experimental data demonstrates that both approaches agree quite well with each other and with the experimental data on hadron production. The enhancement of pion production in central Au+Au (Pb+Pb) collisions relative to scaled pp collisions (the 'kink') is well described by both approaches without involving any phase transition. However, the maximum in the K+/Pi+ ratio at 20 to 30 A.GeV (the 'horn') is missed by ~ 40%. A comparison to the transverse mass spectra from pp and C+C (or Si+Si) reactions shows the reliability of the transport models for light systems. For central Au+Au (Pb+Pb) collisions at bombarding energies above ~ 5 A.GeV, however, the measured K +/- m-theta-spectra have a larger inverse slope parameter than expected from the calculations. The approximately constant slope of K+/-spectra at SPS (the 'step') is not reproduced either. Thus the pressure generated by hadronic interactions in the transport models above ~ 5 A.GeV is lower than observed in the experimental data. This finding suggests that the additional pressure - as expected from lattice QCD calculations at finite quark chemical potential and temperature - might be generated by strong interactions in the early pre-hadronic/partonic phase of central Au+Au (Pb+Pb) collisions

Strangeness dynamics and transverse pressure in relativistic nucleus-nucleus collisions

We investigate hadron production as well as transverse hadron spectra from proton-proton, proton-nucleus and nucleus-nucleus collisions from 2 A·GeV to 21.3 A·TeV within two independent transport approaches (HSD and UrQMD) that are based on quark, diquark, string and hadronic degrees of freedom. The comparison to experimental data on transverse mass spectra from pp, pA and C+C (or Si+Si) reactions shows the reliability of the transport models for light systems. For central Au+Au (Pb+Pb) collisions at bombarding energies above ~5 A·GeV, furthermore, the measured K± transverse mass spectra have a larger inverse slope parameter than expected from the default calculations. We investigate various scenarios to explore their potential effects on the K± spectra. In particular the initial state Cronin effect is found to play a substantial role at top SPS and RHIC energies. However, the maximum in the K+/..+ ratio at 20 to 30 A·GeV is missed by 40% and the approximately constant slope of the K± spectra at SPS energies is not reproduced either. Our systematic analysis suggests that the additional pressure - as expected from lattice QCD calculations at finite quark chemical potential µq and temperature T- should be generated by strong interactions in the early pre-hadronic/partonic phase of central Au+Au (Pb+Pb) collisions

Mapping Internationalism: Congresses and Organisations in the Nineteenth and Twentieth Centuries

The Union of International Associations’ documentation on international non- governmental organizations (INGOs) is a treasure trove for historians and social scientists alike. INGOs are part and parcel of the modern world. They both reflect and influence social, political, cultural and economic conditions around the globe. They occupy a space of human activity in between, but connected to, the market and the state, and this space seems to be growing. The present chapter seeks to show how a historical investigation into this space might benefit from the use of UIA data. As other contributions to this volume have noted, the UIA aims to register the key activities of all INGOs that exist or have ever existed. As anyone familiar with historical databases would immediately admit, a database with such a large geographical (the globe) and temporal span (in principle that of human history, though in practice mostly the past two centuries) cannot, and never will be, complete in its coverage. This is also acknowledged by the UIA and is partly caused by the fact that most of the data is provided by the organizations themselves. For the present purpose – namely the visualization of various long-term developments – we will, however, assume that it can nonetheless offer a representative picture. For practical reasons, we focus on the period between 1800 and 1970, concentrating on two UIA datasets: the annual congress calendar and the Yearbook series, featuring all organizations that meet the UIA’s definition of an INGO