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The centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at sqrt[s_{NN}]=2.76  TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of 2 from peripheral (70%-80%) to central (0%-5%) collisions. The centrality dependence is found to be similar to(More)
A composition analysis of KASCADE air shower data is performed by means of unfolding the two-dimensional frequency spectrum of electron and muon numbers. Aim of the analysis is the determination of energy spectra for elemental groups representing the chemical composition of primary cosmic rays. Since such an analysis depends crucially on simulations of air(More)
The first measurement of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at a center-of-mass energy per nucleon pair √ S NN = 2.76 TeV is presented. For an event sample corresponding to the most central 5% of the hadronic cross section, the pseudorapidity density of primary charged particles at midrapidity is 1584 ± 4(stat) ±(More)
We present the results of an analysis of the large-scale anisotropy of cosmic rays in the PeV range. The Rayleigh formalism is applied to the right ascension distribution of extensive air showers measured by the KASCADE (Karlsruhe Shower Core and Array Detector) experiment. The data set contains about 10 8 extensive air showers in the energy range 0.7–6(More)
The flux of cosmic-ray–induced single hadrons near sea level has been measured with the large hadron calo-rimeter of the KASCADE experiment. The measurement corroborates former results obtained with detectors of smaller size if the enlarged veto of the 304 m 2 calorimeter surface is accounted for. The program CORSIKA/ QGSJET is used to compute the(More)
KASCADE has been designed to measure air showers of primary cosmic-ray energies in the PeV region and to investigate the knee phenomenon in the all-particle energy spectrum. Several observations are measured simultaneously for each event by different detector systems. The experiment started to take data in 1996 and has been completed and extended since(More)
We describe the main features of the extensive air-shower array devoted to the study of cosmic-ray primaries and their interactions at primary energies 10 PeV–1 EeV which is starting operation at Forschungszentrum Karlsruhe. It exploits the existing KASCADE multi-detector facilities, and two new detectors: Grande and Piccolo, with the respective aims of(More)
The interpretation of extensive air shower (EAS) measurements depends on the comparison with EAS simulations. These calculations rely on hadronic interaction models which have to extrapolate into kinemat-ical and energy regions not covered by present-day collider experiments. Therefore, it is necessary to check the reliability of the interaction models(More)
We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at sqrt[S(NN)] =2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η|<0.8) and transverse momentum range 0.2<p t<5.0 GeV/c. The elliptic flow signal v₂, measured using the 4-particle(More)
The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >10(20) eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within approximately 50 Mpc through interactions with the cosmic microwave background. As there are no sufficiently powerful accelerators within this distance from the Galaxy, explanations for(More)