1,110 research outputs found
Search for the eta-mesic nuclei by means of COSY-11, WASA-at-COSY and COSY-TOF detector systems
We review status and perspectives of the search for the light eta-mesic
nuclei using COSY-11, WASA-at-COSY and COSY-TOF detector systems.Comment: Invited talk at the International Symposium on Mesic Nuclei, Krakow,
16 June 201
Real time statistical analysis of acoustic emission signals for flaw monitoring systems
Small structures are checked by monitoring samples for acoustical signal count. Flaws are located by observing relatively high acoustical activity within given area. Acoustical monitoring has been extended to large structures by dividing large samples into small areas and then monitoring each area separately
Search for eta-mesic helium using the WASA-AT-COSY detector
We conduct a search for the 4He-eta bound state with the WASA-at-COSY
facility via the measurement of the excitation function for the reaction
dd->3Heppi-. In first experiment performed in June 2008, we used COSY deuteron
beam with a slowly ramped beam momentum corresponding to a variation of the
excess energy for the 4He-eta system from -51.4 MeV to 22 MeV. Here we report
on the status of the measurement and the data evaluation.Comment: Presented at Symposium on Meson Physics: extended COSY-11
collaboration meeting, Cracow, Poland, 1-4 Oct 2008, 8 pages, 5 figures
Measurement of the invariant mass distributions for the pp -> ppeta' reaction at excess energy of Q = 16.4 MeV
The proton-proton and proton-eta' invariant mass distributions have been
determined for the pp -> ppeta' reaction at an excess energy of Q = 16.4 MeV.
The measurement was carried out using the COSY-11 detector setup and the proton
beam of the cooler synchrotron COSY. The shapes of the determined invariant
mass distributions are similar to those of the pp -> ppeta reaction and reveal
an enhancement for large relative proton-proton momenta. This result, together
with the fact that the proton-eta interaction is much stronger that the
proton-eta' interaction, excludes the hypothesis that the observed enhancement
is caused by the interaction between the proton and the meson
When Is Workers\u27 Compensation Payable for Subsequent Nonemployment Injuries?—In Search of the Minnesota Rule
Kaon pair production close to threshold
The total cross section of the reaction pp->ppK+K- has been measured at
excess energies Q=10 MeV and 28 MeV with the magnetic spectrometer COSY-11. The
new data show a significant enhancement of the total cross section compared to
pure phase space expectations or calculations within a one boson exchange
model. In addition, we present invariant mass spectra of two particle
subsystems. While the K+K- system is rather constant for different invariant
masses, there is an enhancement in the pK- system towards lower masses which
could at least be partially connected to the influence of the Lambda(1405)
resonance.Comment: accepted for publication in Phys. Lett.
Study of the Low Energy Dynamics in the ppK+K- System with the Cosy-11 Magnetic Spectrometer
The near threshold production of K+K- pairs in proton-proton collisions has
been investigated at the cooler synchrotron COSY below and above the threshold
for the \phi meson production. The experimental excitation function determined
for the pp-->ppK+K- reaction differs from theoretical expectations including
proton-proton final state interaction. The discrepancy may be assigned to the
influence of K+K- or pK interaction. In this article we present distributions
of the cross section for the pp-->ppK+K- reaction as a function of the
invariant masses of two and three particle subsystems at excess energies of
Q=10 MeV and 28 MeV.Comment: Presented at the Symposium on Meson Physics, Cracow, 01-04 October
200
Underwater detection of dangerous substances: status the SABAT project
The Neutron Activation Analysis (NAA) plays an exceptional role in the modern
nuclear engineering, especially in detection of hazardous substances. However,
in the aquatic environment, there are still many problems to be solved for
effective usage of this technique. We present status of SABAT (Stoichiometry
Analysis By Activation Techniques), one of the projects aiming at construction
of an underwater device for non-invasive threat detection based on the NAA
Controlled exchange interaction for quantum logic operations with spin qubits in coupled quantum dots
A two-electron system confined in two coupled semiconductor quantum dots is
investigated as a candidate for performing quantum logic operations on spin
qubits. We study different processes of swapping the electron spins by
controlled switching on/off the exchange interaction. The resulting spin swap
corresponds to an elementary operation in quantum information processing. We
perform a direct time evolution simulations of the time-dependent Schroedinger
equation. Our results show that -- in order to obtain the full interchange of
spins -- the exchange interaction should change smoothly in time. The presence
of jumps and spikes in the corresponding time characteristics leads to a
considerable increase of the spin swap time. We propose several mechanisms to
modify the exchange interaction by changing the confinement potential profile
and discuss their advantages and disadvantages
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