260 research outputs found
Abwehr ausländischer Staatsfonds: Aktive Industriepolitik oder "neue Schutzzäune"?
Sollte das Engagement ausländischer Investoren, insbesondere Staatsfonds, in Deutschland kontrolliert werden? Roland Koch, Ministerpräsident des Landes Hessen, warnt vor möglichen staatlich gelenkten Investoren bzw. staatlich aufgelegten Fonds, die vermehrt strategisch agieren, um die Interessen ihrer Länder in für sie interessanten Märkten durchzusetzen. Seiner Meinung nach sollte Vorsorge getroffen werden, damit es nicht zu politisch motivierten Marktbeeinflussungen komme. Denkbar sei eine Anmeldepflicht größerer Transaktionen. Rainer Brüderle, FDP-Fraktion, dagegen, sieht bei einer Genehmigungspflicht bereits den "Abschied" vom freien Handel und betont, dass gerade die Deutschen von offenen Märkten und ausländischem Kapital profitieren. Auch Gunter Schall, BDI, ist der Ansicht, dass zur Aufrechterhaltung eines funktionsfähigen Marktes kartell- und wettbewerbsrechtliche Instrumente besser geeignet sind als Investitionsbeschränkungen. Allerdings erscheinen Ausnahmen in bestimmten Fällen gerechtfertigt. Diese Auffassung vertritt auch Justus Haucap, Universität Erlangen-Nürnberg. Der beste Schutz vor politischer Einflussnahme sei der funktionierende Wettbewerb auf den Produktmärkten. Anton F. Börner, Bundesverband des deutschen Groß- und Außenhandels, fordert anstatt eines Schutzwalles gegen ausländische Investitionen Reformen zur Verbesserung des Standortes Deutschland. Das Land lebe von seinen offenen Grenzen und seiner liberalen Wirtschaftsordnung; Merkantilismus und Protektionismus "im Kleid nationaler Interessen gefährde die Wettbewerbsfähigkeit". Claus Matecki, DGB, plädiert dagegen für strikte Meldepflichten und eine Aufsichtsbehörde, die die Investitionen in strategisch relevanten Bereichen kontrollieren sollte. Den Regulierungsbedarf jedoch auf Staatsfonds zu beschränken, hält er für "ordnungspolitisch ehrenhaft, ökonomisch aber nicht stichhaltig".Direktinvestition, Auslandsinvestitionsrecht, Industriepolitik, Wettbewerb, Regulierung, Protektionismus, Deutschland
Photoproduction of pi0 omega off protons for E(gamma) < 3 GeV
Differential and total cross-sections for photoproduction of gamma proton to
proton pi0 omega and gamma proton to Delta+ omega were determined from
measurements of the CB-ELSA experiment, performed at the electron accelerator
ELSA in Bonn. The measurements covered the photon energy range from the
production threshold up to 3GeV.Comment: 8 pages, 13 figure
Cosmological flux noise and measured noise power spectra in SQUIDs
The understanding of the origin of magnetic flux noise commonly
observed in superconducting devices such as SQUIDS and qubits is still a major
unsolved puzzle. Here we discuss the possibility that a significant part of the
observed low-frequency flux noise measured in these devices is ultimately
seeded by cosmological fluctuations. We consider a theory where a primordial
flux noise field left over in unchanged form from an early inflationary or
quantum gravity epoch of the universe intrinsically influences the phase
difference in SQUIDs and qubits. The perturbation seeds generated by this field
can explain in a quantitatively correct way the form and amplitude of measured
low-frequency flux noise spectra in SQUID devices if one takes as a source of
fluctuations the primordial power spectrum of curvature fluctuations as
measured by the Planck collaboration. Our model predicts flux noise with a
spectrum given by an spectrum, where is the spectral
index of the near-scale invariant primordial density fluctuations. For the
typical amplitude of this cosmologically generated universal flux noise we
theoretically calculate the average value at 1Hz. These theoretical predictions are in excellent agreement with
recent low-frequency flux noise measurements of various experimental groups.
Magnetic flux noise, so far mainly considered as a nuisance for electronic
devices, may thus contain valuable information about fluctuation spectra in the
very early universe.Comment: 7 pages, 3 figures. Newly written updated version. Final version as
accepted by Scientific Report
Study of the reaction
The reaction has been studied with the CBELSA
detector at the tagged photon beam of the Bonn electron stretcher facility. The
reaction shows contributions from , and
as intermediate states. A partial wave analysis suggests that the
reaction proceeds via formation of six resonances,
, , ,
, , , and two
nucleon resonances and , for which pole
positions and decay branching ratios are given.Comment: 13 pages, 10 figures, 7 table
Photoproduction of eta mesons off protons for photon energies from 0.75 GeV to 3 GeV
Total and differential cross sections for the reaction p(gamma, eta)p have
been measured for photon energies in the range from 750 MeV to 3 GeV. The
low-energy data are dominated by the S11 wave which has two poles in the energy
region below 2 GeV. Eleven nucleon resonances are observed in their decay into
p eta. At medium energies we find evidence for a new resonance N(2070)D15 with
(mass, width) = (2068+-22, 295+-40) MeV. At photon energies above 1.5 GeV, a
strong peak in forward direction develops, signalling the exchange of vector
mesons in the t channel.Comment: LaTeX, 4 pages including 4 eps-figures, submitted to Phys. Rev. Lett.
The publication of hep-ex/0311045 is accompanied by hep-ex/0407022 on
photoproduction of neutral pions, submitted to Phys. Rev. Lett. Fits
published in the latest version are based on additional data, new beam
asymmetry data from GRAAL are included, for instance. The data demanded more
resonant contributions which were studied in detail. PWA reference adde
Neutral pion photoproduction off protons in the energy range 0.3 GeV < E(gamma) < 3 GeV
Single pi0 photoproduction has been studied with the CB-ELSA experiment at
Bonn using tagged photon energies between 0.3 and 3.0 GeV. The experimental
setup covers a very large solid angle of about 98% of 4 pi. Differential cross
sections (d sigma)/(d Omega) have been measured. Complicated structures in the
angular distributions indicate a variety of different resonances being produced
in the s channel intermediate state gamma p --> N* (Delta*) --> p pi0. A
combined analysis including the data presented in this letter along with other
data sets reveals contributions from known resonances and evidence for a new
resonance N(2070)D15.Comment: LaTeX file, 4 pages, 4 encapsulated postscript figures, submitted to
Phys. Rev. Lett. The publication of hep-ex/0407022 is accompanied by
hep-ex/0311045 on photoproduction of eta mesons. Reference [3]: changed,
reference [17]: citation added. Figure 3, 4: SAID added up to 2 GeV for
comparison, update
N* and Delta* decays into N pi0 pi0
Decays of baryon resonances in the second and the third resonance region into
N pi0 pi0 are studied by photoproduction of two neutral pions off protons.
Partial decay widths of N* and Delta* resonances decaying into Delta(1232) pi,
N(\pi\pi)_{S}, N(1440)P_{11} pi, and N(1520)D_{13} pi are determined in a
partial wave analysis of this data, and data from other reactions. Several
partial decay widths were not known before. Interesting decay patterns are
observed which are not even qualitatively reproduced by quark model
calculations. In the second resonance region, decays into Delta(1232) pi
dominate clearly. The N(\pi\pi)_{S}-wave provides a significant contribution to
the cross section, especially in the third resonance region. The P_{13}(1720)
properties found here are at clear variance to PDG values.Comment: 13 pages, 4 figures, long author's lis
Addendum 2 to P253: a high sensitivity investigation of and neutral hyperon decays using a modified beam
Direct search for light gluinos
We present the results for a direct search for light gluinos through the appearance of with high transverse momentum in the vacuum tank of the NA48 experiment at CERN. We find one event within a lifetime range of s and another one between s. Both events are consistent with the expected background from neutrons in the beam, produced by 450 GeV protons impinging on the Be targets, which interact with the residual air in the tank. From these data we give limits on the production of the hypothetical bound state, the hadron, and its decay in the mass range between 1 and 5~GeV
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
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