2,808 research outputs found
Preliminary study of kaonic deuterium X-rays by the SIDDHARTA experiment at DAFNE
The study of the KbarN system at very low energies plays a key role for the
understanding of the strong interaction between hadrons in the strangeness
sector. At the DAFNE electron-positron collider of Laboratori Nazionali di
Frascati we studied kaonic atoms with Z=1 and Z=2, taking advantage of the
low-energy charged kaons from Phi-mesons decaying nearly at rest. The SIDDHARTA
experiment used X-ray spectroscopy of the kaonic atoms to determine the
transition yields and the strong interaction induced shift and width of the
lowest experimentally accessible level (1s for H and D and 2p for He). Shift
and width are connected to the real and imaginary part of the scattering
length. To disentangle the isospin dependent scattering lengths of the
antikaon-nucleon interaction, measurements of Kp and of Kd are needed. We
report here on an exploratory deuterium measurement, from which a limit for the
yield of the K-series transitions was derived: Y(K_tot)<0.0143 and
Y(K_alpha)<0.0039 (CL 90%). Also, the upcoming SIDDHARTA-2 kaonic deuterium
experiment is introduced.Comment: Accepted by Nuclear Physics
Cercetări privind entomofauna de coleoptere (coleoptera) din unele culturi agricole din N-E Moldovei
The purpose of these research is to identify the useful entomofauna from the agricultural crops which have been taken for the study: maize and cabbage. The researches were carried out in the Adamachi station which belongs to “Ion Ionescu de la Brad” University of Iasi, Romania. The biological material was sampled by means of the Barber soil traps from 3rd of June until 13th of September 2016. In total, 15 samples were made for every crop. The traps were placed every five in a row. To prevent the maceration of insects, a conservative liquid was used (water+ washing powder) in proportion of 16%. After finishing the experiments, the insects were bringing to the laboratory of Entomology in order to be counted and determined. From the Coleoptera order, the most dominant species are:-within the crop of maize: Amara aenea (Carabidae)-5 samples; Coccinella septempunctata (Coccinellidae)-15 samples;-within the crop of cabbage:Brachinus crepitans(Carabidae)-9 samples
X-ray transition yields of low-Z kaonic atoms produced in Kapton
The X-ray transition yields of kaonic atoms produced in Kapton polyimide
(C22H10N2O5) were measured for the first time in the SIDDHARTA experiment.
X-ray yields of the kaonic atoms with low atomic numbers (Z = 6, 7, and 8) and
transitions with high principal quantum numbers (n = 5-8) were determined. The
relative yield ratios of the successive transitions and those of
carbon-to-nitrogen (C:N) and carbon-to-oxygen (C:O) were also determined. These
X-ray yields provide important information for understanding the capture ratios
and cascade mechanisms of kaonic atoms produced in a compound material, such as
Kapton.Comment: Accepted in Nucl. Phys. A (2013
First measurement of kaonic helium-3 X-rays
The first observation of the kaonic 3He 3d - 2p transition was made using
slow K- mesons stopped in a gaseous 3He target. The kaonic atom X-rays were
detected with large-area silicon drift detectors using the timing information
of the K+K- pairs of phi-meson decays produced by the DAFNE e+e- collider. The
strong interaction shift of the kaonic 3He 2p state was determined to be -2+-2
(stat)+-4 (syst) eV.Comment: Accepted for publication in Phys. Lett.
A New Measurement of Kaonic Hydrogen X rays
The system at threshold is a sensitive testing ground for low
energy QCD, especially for the explicit chiral symmetry breaking. Therefore, we
have measured the -series x rays of kaonic hydrogen atoms at the DANE
electron-positron collider of Laboratori Nazionali di Frascati, and have
determined the most precise values of the strong-interaction energy-level shift
and width of the atomic state. As x-ray detectors, we used large-area
silicon drift detectors having excellent energy and timing resolution, which
were developed especially for the SIDDHARTA experiment. The shift and width
were determined to be eV and
eV, respectively. The new
values will provide vital constraints on the theoretical description of the
low-energy interaction.Comment: 5 figures, submitted to Physics Letters
Kaonic hydrogen X-ray measurement in SIDDHARTA
Kaonic hydrogen atoms provide a unique laboratory to probe the kaon-nucleon
strong interaction at the energy threshold, allowing an investigation of the
interplay between spontaneous and explicit chiral symmetry breaking in
low-energy QCD. The SIDDHARTA Collaboration has measured the -series X rays
of kaonic hydrogen atoms at the DANE electron-positron collider of
Laboratori Nazionali di Frascati, and has determined the most precise values of
the strong-interaction induced shift and width of the atomic energy level.
This result provides vital constraints on the theoretical description of the
low-energy interaction.Comment: 11 pages, 7 figures, Nuclear Physics A (in press) Special Issue on
Strangeness Nuclear Physic
Technical Design Report for the PANDA Solenoid and Dipole Spectrometer Magnets
This document is the Technical Design Report covering the two large
spectrometer magnets of the PANDA detector set-up. It shows the conceptual
design of the magnets and their anticipated performance. It precedes the tender
and procurement of the magnets and, hence, is subject to possible modifications
arising during this process.Comment: 10 pages, 14MB, accepted by FAIR STI in May 2009, editors: Inti
Lehmann (chair), Andrea Bersani, Yuri Lobanov, Jost Luehning, Jerzy Smyrski,
Technical Coordiantor: Lars Schmitt, Bernd Lewandowski (deputy),
Spokespersons: Ulrich Wiedner, Paola Gianotti (deputy
Low-energy kaon-nucleon/nuclei interaction studies at DAΦNE (SIDDHARTA and AMADEUS experiments)
The DAΦNE electron-positron collider at the Laboratori Nazionali di Frascati of INFN has made available a unique-quality low-energy negative-kaons “beam”. The SIDDHARTA experiment used this beam to perform unprecedented
precision measurements on kaonic atoms, while the AMADEUS experiment plans to perform in the coming years precision measurements on kaon-nuclei interactions at low-energies, in particular to study the kaonic nuclei. The two experiments are briefly presented in this paper
Results from the kaonic hydrogen X-ray measurement at DAFNE and outlook to future experiments
The system at rest plays a key role for the understanding of strong interaction of hadrons with strangeness involved. The experiment SIDDHARTA used X-ray spectroscopy of kaonic atoms to measure the strong interaction induced shift and width of the ground state. It was the first experiment on kaonic He3 and deuterium ever, kaonic hydrogen was measured with improved precision resulting in \epsilon_{1s} = -283 \pm 36 \mbox{(stat)} \pm 6 \mbox{(syst)} eV and \Gamma_{1s} = 541 \pm 89 \mbox{(stat)} \pm 22 \mbox{(syst)} eV. Additionally a scheme for an improved future experiment on kaonic deuterium is introduced in this contribution
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