469 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
Pre-Education Programs: A Comprehensive Project at Henry Ford Community College
Henry Ford Community College (HFCC) in Dearbom, Michigan is a two-year institution of higher education serving a diverse student population of approximately 13,000 students. In addition to providing a broad array of technical and vocational programs, the College provides the first two years of a baccalaureate program. However, the transferability of these programs is not assured. In the absence of a mandated state-wide curriculum, two- and four-year colleges and universities in Michigan develop courses and programs independently, and the transfer of courses between institutions is determined independently by the respective departments. The end result is often loss of credit when a community college student transfers. Other problems faced prospective education majors as well. Students were justifiably apprehensive about the suitability of their academic preparation for the challenges they would confront at the four-year institution. To address this and other problems, HFCC initiated a comprehensive project to develop a structured teacher education program. The project consisted of two components: 1) creation of pre-education programs and 2) institution of articulated transfer agreements as a result of collaboration with neighboring universities. The success of this reform is underscored by a dramatic increase in HFCC pre-education majors from 354 students in 1994 to 697 in 1997, with 80 students designating minority status in 1994 and 179 in 1997
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
Search for He-eta bound states with the WASA-at-COSY facility
The existence of eta-mesic nuclei in which the eta meson is bound in a
nucleus by means of the strong interaction was postulated already in 1986,
albeit not yet confirmed it by experiment. The discovery of this new kind of an
exotic nuclear matter would be very important as it might allow for a better
understanding of the eta meson structure and its interaction with nucleons. The
search for eta-mesic helium 4He-eta is carried out with high statistics and
high acceptance with the WASA detector, installed at the cooler synchrotron
COSY of the Research Center Juelich. The search is conducted via the
measurement of the excitation function for selected decay channels of the
4He-eta system. In the experiment, performed in November 2010, two reactions
dd->(4He-eta)bs ->3He p pi- and dd->(4He-eta)bs ->3He p pi0 were measured with
a beam momentum ramped from 2.127GeV/c to 2.422GeV/c. The report includes the
description of the experimental method and status of the measurement.Comment: Presented at the Erice School on Nuclear Physics 2011. 5 pages, 3
figure
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
Search for eta-mesic Helium with the WASA-at-COSY detector
A search for the 4He-eta bound state via exclusive measurement of the
excitation function for the dd->3Heppi- reaction, was performed at the Cooler
Synchrotron COSY-Juelich with the WASA-at-COSY detection system. The data were
taken during a slow acceleration of the beam from 2.185 GeV/c to 2.400 GeV/c
crossing the kinematic threshold for the eta production in the dd -> 4He-eta
reaction at 2.336 GeV/c. The corresponding excess energy in the 4He-eta system
varied from -51.4 MeV to 22 MeV. The shape of the excitation function for the
dd -> 3Heppi- was examined. No signal of the 4He-eta bound state was observed
in the excitation function.Comment: 4 pages, 5 figures, to appear in proceedings of MESON201
Measurement of signal-to-noise ratio in straw tube detectors for PANDA forward tracker
PANDA forward tracker consist of self supporting straw tube detector for reconstruction of trajectories of charged particles passes through it, particle identification. The basic properties of straw tube detector and signal-to-noise ratio with results are presented in this paper
Spin observables of the reaction pd-3He eta and quasi-bound 3He-eta pole
A formalism for spin observables of the reaction
is derived in a model independent way.
The general case with a full set of six independent spin amplitudes is
studied. Furthermore, approximations by five and four spin amplitudes are
investigated in the near threshold region. This region is of great interest to
search for a quasi-bound state, in particular, by measurement of
energy dependence of relative phases of s- and p-wave amplitudes. Complete
polarization experiments, allowing determination of spin amplitudes, are
analyzed. It is shown that measurement of only analyzing powers and spin
correlation coefficients hardly allows one to separate the s- and p-wave
amplitudes, but additional measurement of polarization transfer coefficients
simplifies this problem. Specific observables, given by products of one s- and
one p-wave amplitudes, are found. Measurement of these observables will provide
new independent information on the pole position.Comment: 16 pages, Latex. Submitted to Nuclear Physics
Monitoring of the accelerator beam distributions for internal target facilities
We describe a direct method for monitoring the geometrical dimensions of a
synchrotron beam at the target position for internal target installations. The
method allows for the observation of the proton beam size as well as the
position of the beam relative to the target. As a first demonstration of the
technique, we present results obtained by means of the COSY-11 detection system
installed at the cooler synchrotron COSY. The influence of the stochastic
cooling on the COSY proton beam dimensions is also investigated.Comment: 7 pages, 8 figures, Submitted to Nucl. Inst. & Meth.
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