Klein-Bosing C.,Institute For Kernphysik |
Klein-Bosing C.,Helmholtz Center for Heavy Ion Research
Journal of Physics G: Nuclear and Particle Physics | Year: 2011
For a quantitative interpretation of reconstructed jet properties in heavy-ion collisions, it is paramount to characterize the contribution from the underlying event and the influence of background fluctuations on the jet signal. In addition to the pure number fluctuations, region-to-region correlated background within one event can enhance or deplete locally the level of background and modify the jet energy. We show the first detailed assessment of background effects using different probes embedded into heavy-ion data and quantify their influence on the reconstructed jet spectrum. © CERN 2011. Published under licence by IOP Publishing Ltd.
Langanke K.,Helmholtz Center for Heavy Ion Research |
Langanke K.,Institute For Kernphysik |
Langanke K.,Frankfurt Institute for Advanced Studies |
Schatz H.,Michigan State University
Physica Scripta | Year: 2013
Short-lived exotic nuclei play essential roles in the dynamics of many stellar objects and their associated nucleosynthesis, including core-collapse and thermonuclear supernovae, novae, x-ray bursters and mass-accreting neutron stars in binary systems. To produce such nuclei and to study their properties requires radioactive ion-beam facilities. While the short-lived nuclei on the neutron-deficient side of the chart of nuclei are often within reach at current experimental facilities, albeit not necessarily with the beam intensities needed, the extremely neutron-rich nuclei, required for an understanding of the synthesis of heavy elements in the Universe by the astrophysical r-process, have to wait, in most cases, for the next-generation radioactive ion-beam facilities. This paper discusses highlights of recent experimental and theoretical advances in determining the properties of exotic nuclei and the further need for reliable studies of astrophysical objects such as supernovae, novae, x-ray bursters and neutron stars. © 2013 The Royal Swedish Academy of Sciences.
Klein-Boesing C.,Institute For Kernphysik |
Klein-Boesing C.,Helmholtz Center for Heavy Ion Research |
McLerran L.,Brookhaven National Laboratory |
McLerran L.,Central China Normal University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014
Geometric scaling is a property of hadronic interactions predicted by theories of gluon saturation and expressing rates in terms of dimensionless ratios of transverse momentum to the saturation momentum. In this paper we consider production of photons in pp, dAu and AuAu collisions at sNN=200GeV (RHIC) and in PbPb collisions at sNN=2760GeV (LHC) and show that the yield of direct photons in the transverse momentum range 1GeV < p T ≤ 4GeV/c satisfies geometric scaling. Excellent agreement with geometric scaling is obtained with the only free parameter of the saturation momentum determined previously via the dependence of the saturation momentum upon Bjorken x and centrality. © 2014 The Authors.
Balaguer Rios D.,Institute For Kernphysik
Nuovo Cimento della Societa Italiana di Fisica C | Year: 2012
The A4 Collaboration at the MAMI facility has measured, at backward angles and at Q2 = 0.23 (GeV/c)2 and Q2 = 0.35 (GeV/c)2, the asymmetry in the elastic and quasielastic scattering of normally polarized electrons on hydrogen and deuterium, respectively. Some preliminary results will be presented. © Società Italiana di Fisica.
Skurzok M.,Jagiellonian University |
Moskal P.,Jagiellonian University |
Moskal P.,Institute For Kernphysik |
Krzemie W.,Jagiellonian University
Progress in Particle and Nuclear Physics | Year: 2012
The existence of η-mesic nuclei in which the η meson is bound with nucleus by means of the strong interaction was postulated already in 1986, however till now no experiment confirmed it empirically. Discovering of this new kind of an exotic nuclear matter would be very important as it might allow for better understanding of the η meson structure and its interaction with nucleons. The search for η-mesic helium ( 4He-η) is carried out with high statistic and high acceptance by means of the WASA detector, installed at the cooler synchrotron COSY in the Research Center Jlich. The search is conducted via the measurement of the excitation function for the chosen decay channels of the 4He-η system. In the experiment performed in November 2010 two reactions dd→( 4He -η)bs→ 3Hep π- and dd→( 4He -η)bs→ 3Hen π0 were measured with the beam momentum ramped from 2.127 GeV/c to 2.422 GeV/c. The report includes the description of experimental method and status of the measurement. © 2012 Elsevier B.V. All rights reserved.
Rebel H.,Institute For Kernphysik
AIP Conference Proceedings | Year: 2010
When thinking of an innovation that has truly changed our world, it is the laser. Right after discovery back in 1960, it is immediately propelled to a public star. People loved the mystery around this new kind of light. It was soon recognized as a symbol of our entry into the future: The Laser Age has started. Newspapers speculated about "death rays" as new weapons. It did not take long time until it appeared in Science fiction movies. However reality was much more beneficial and even more diverse. This device has managed to exceed the wildest predictions of the early laser pioneers when it comes to its applications. Today lasers are not a weird scientist's toy, but are commonly used in our everyday life. Of course, nothing of that was foreseen in the early 1950s. Important fundamentals of lasers have been laid already in 1917 by Albert Einstein, introducing the Einstein coefficient of stimulated emission, and subsequent experimental work by Rudolf Ladenburg, Willis Lamb, Alfred Kastler and others. © 2010 American Institute of Physics.
Heide M.,Institute For Kernphysik
Journal of Physics: Conference Series | Year: 2014
ALICE measured electrons from inclusive heavy-avour hadron decays and beautyhadron decays at mid-rapidity in pp collisions at S = 7 TeV and 2.76 TeV and p-Pb collisions at SNN = 5.02 TeV. For both pp collision energies, pT-differential electron production cross sections are presented and compared to pQCD predictions. For p-Pb collisions, the pT-dependent nuclear modification factor of electrons from inclusive heavy-avour hadron decays is presented.
Rios D.B.,Institute For Kernphysik
Hyperfine Interactions | Year: 2011
The A4 collaboration at the MAMI facility has measured at backward angles the asymmetry in the elastic and quasielastic scattering of transversely polarized electrons on hydrogen and deuterium respectively. Some preliminary results will be presented. © 2011 Springer Science+Business Media B.V.
Baunack S.,Institute For Kernphysik
Hyperfine Interactions | Year: 2011
The A4 collaboration at the MAMI accelerator at Mainz investigates the contribution of strange quarks to the form factors of the nucleon by measuring the parity violating asymmetry APV in the cross section of elastic scattering of longitudinally polarized electrons off hydrogen and deuterium. Recently, measurements at backward angles at a four momentum transfer of Q2 = 0.22 GeV2 were completed. Together with previous results at forward angles at the same momentum transfer, the strange electric and magnetic form factors GEs and GMs can be disentangled. © 2011 Springer Science+Business Media B.V.
Huege T.,Institute For Kernphysik
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2010
In small-scale experiments such as CODALEMA and LOPES, radio detection of cosmic rays has demonstrated its potential as a technique for cosmic ray measurements up to the highest energies. Radio detection promises measurements with high duty-cycle, allows a direction reconstruction with very good angular resolution, and provides complementary information on energy and nature of the cosmic ray primaries with respect to particle detectors at ground and fluorescence telescopes. Within the Pierre Auger Observatory, we tackle the technological and scientific challenges for an application of the radio detection technique on large scales. Here, we report on the results obtained so far using the Southern Auger site and the plans for an engineering array of radio detectors covering an area of ∼20 km2. © 2009 Elsevier B.V. All rights reserved.