1,355 research outputs found
Comment on "Material Evidence of a 38 MeV Boson"
In the recent preprint 1202.1739 it was claimed that preliminary data
presented by COMPASS at recent conferences confirm the existence of a resonant
state of mass 38 MeV decaying to two photons. This claim was made based on
structures observed in two-photon mass distributions which however were shown
only to demonstrate the purity and mass resolution of the {\pi}0 and {\eta}
signals. The additional structures are understood as remnants of secondary
interactions inside the COMPASS spectrometer. Therefore, the COMPASS data do
not confirm the existence of this state.Comment: 2 pages, 7 figure
Comparative study of hormonal counterregulation during GCIIS-guided hypoglycemia tests using human Proinsulin and Human Insulin (recombinant DNA)
Schlechte Scanvorlage
Hormonal Counterregulation during standardized Hypoglycemia Test comparing Biosynthetic Human Proinsulin and Human Insulin
Hormonal counterregulation during standardized Hypoglycemia Test comparing Biosynthetic Human Proinsulin and Insulin
Angular Correlations in Internal Pair Conversion of Aligned Heavy Nuclei
We calculate the spatial correlation of electrons and positrons emitted by
internal pair conversion of Coulomb excited nuclei in heavy ion collisions. The
alignment or polarization of the nucleus results in an anisotropic emission of
the electron-positron pairs which is closely related to the anisotropic
emission of -rays. However, the angular correlation in the case of
internal pair conversion exhibits diverse patterns. This might be relevant when
investigating atomic processes in heavy-ion collisions performed at the Coulomb
barrier.Comment: 27 pages + 6 eps figures, uses revtex.sty and epsf.sty,
tar-compressed and uuencoded with uufile
Climate informed engineering: An essential pillar of industry 4.0 transformation
Breakthroughs in computing have led to development of new generations of Earth Systems Models providing detailed information on how our planet may locally respond to the ongoing global warming. Access to such climate information systems presents an unprecedented opportunity for engineers to make tangible contributions to climate adaptation through integration of climate information in their products, designs, and services. We introduce the concept of “Climate Informed Engineering” (CIE) as an emerging interdisciplinary field integrating climatic considerations in engineering products and services. The concept behind CIE is to enable engineers to build infrastructure, devices, sensors or develop new materials and processes that are informed by climate and climate change information. We believe CIE will be an increasingly important dimension of Engineering Science resonating with engineers and scientists with different backgrounds
Measurement of the 187Re({\alpha},n)190Ir reaction cross section at sub-Coulomb energies using the Cologne Clover Counting Setup
Uncertainties in adopted models of particle+nucleus optical-model potentials
directly influence the accuracy in the theoretical predictions of reaction
rates as they are needed for reaction-network calculations in, for instance,
{\gamma}-process nucleosynthesis. The improvement of the {\alpha}+nucleus
optical-model potential is hampered by the lack of experimental data at
astrophysically relevant energies especially for heavier nuclei. Measuring the
Re187({\alpha},n)Ir190 reaction cross section at sub-Coulomb energies extends
the scarce experimental data available in this mass region and helps
understanding the energy dependence of the imaginary part of the
{\alpha}+nucleus optical-model potential at low energies. Applying the
activation method, after the irradiation of natural rhenium targets with
{\alpha}-particle energies of 12.4 to 14.1 MeV, the reaction yield and thus the
reaction cross section were determined via {\gamma}-ray spectroscopy by using
the Cologne Clover Counting Setup and the method of {\gamma}{\gamma}
coincidences. Cross-section values at five energies close to the
astrophysically relevant energy region were measured. Statistical model
calculations revealed discrepancies between the experimental values and
predictions based on widely used {\alpha}+nucleus optical-model potentials.
However, an excellent reproduction of the measured cross-section values could
be achieved from calculations based on the so-called Sauerwein-Rauscher
{\alpha}+nucleus optical-model potential. The results obtained indicate that
the energy dependence of the imaginary part of the {\alpha}+nucleus
optical-model potential can be described by an exponential decrease. Successful
reproductions of measured cross sections at low energies for {\alpha}-induced
reactions in the mass range 141{\leq}A{\leq}187 confirm the global character of
the Sauerwein-Rauscher potential
Meson spectroscopy with COMPASS
The COMPASS fixed-target experiment at CERN SPS is dedicated to the study of
hadron structure and dynamics. In the physics programme using hadron beams, the
focus is on the detection of new states, in particular the search for
exotic states and glueballs. After a short pilot run in 2004 (190 GeV/c
negative pion beam, lead target), we started our hadron spectroscopy programme
in 2008 by collecting an unprecedented statistics with a negative hadron beam
(190 GeV/c) on a liquid hydrogen target. A similar amount of data with positive
hadron beam (190 GeV/c) has been taken in 2009, as well as some additional data
with negative beam on nuclear targets. The spectrometer features a large
angular acceptance and high momentum resolution and also good coverage by
electromagnetic calorimetry, crucial for the detection of final states
involving or . A first important result is the observation of a
significant spin exotic signal consistent with the disputed
in the pilot run data. This result was recently published. We
present an overview of the status of various ongoing analyses on the 2008/09
data.Comment: 6 pages, 6 figures, to appear in the proceedings of the International
Nuclear Physics Conference 2010, Vancouver, Canada, 04-09 Jul 201
Derivation of Boltzmann Principle
We present a derivation of Boltzmann principle
based on classical mechanical models of thermodynamics. The argument is based
on the heat theorem and can be traced back to the second half of the nineteenth
century with the works of Helmholtz and Boltzmann. Despite its simplicity, this
argument has remained almost unknown. We present it in a modern, self-contained
and accessible form. The approach constitutes an important link between
classical mechanics and statistical mechanics
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