168 research outputs found
Spin Correlation Coefficients in pp-->pnpi+ from 325 to 400 MeV
The spin correlation coefficient combinations Axx + Ayy, Axx - Ayy and the
analyzing powers Ay(theta) were measured for pp-->pnpi+ at beam energies of
325, 350, 375 and 400 MeV. A polarized internal atomic hydrogen target and a
stored, polarized proton beam were used. These polarization observables are
sensitive to contributions of higher partial waves. A comparison with recent
theoretical calculations is provided.Comment: 8 Pages, 1 Table, 5 Figures. Accepted for publication in Phys. Lett.
Spin correlations in pion production near threshold
A first measurement of longitudinal as well as transverse spin correlation
coefficients for the reaction was made using a
polarized proton target and a polarized proton beam. We report kinematically
complete measurements for this reaction at 325, 350, 375 and 400 MeV beam
energy. The spin correlation coefficients and the analyzing power as well as angular
distributions for and the polarization observables
were extracted. Partial wave cross sections for dominant
transition channels were obtained from a partial wave analysis that included
the transitions with final state angular momenta of . The measurements
of the polarization observables are compared
with the predictions from the J\"ulich meson exchange model. The agreement is
very good at 325 MeV, but it deteriorates increasingly for the higher energies.
At all energies agreement with the model is better than for the reaction
.Comment: Preprint, 21 pp, submitted to Phys. Rev. C. Keywords: Mesons,
Polarization, Spin Correlations, Few body system
Search for a-Cluster States in the Giant Resonance Region
Supported by the National Science Foundation and Indiana Universit
First Cooler Test Run For p+p → p+n+(pi+)(CE03)
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Heavy Meson Production in NN Collisions with Polarized Beam and Target -- A new facility for COSY
The study of near--threshold meson production in pp and pd collisions
involving polarized beams and polarized targets offers the rare opportunity to
gain insight into short--range features of the nucleon--nucleon interaction.
The Cooler Synchrotron COSY at FZ--J\"ulich is a unique environment to perform
such studies. Measurements of polarization observables require a cylindrically
symmetrical detector, capable to measure the momenta and the directions of
outgoing charged hadrons. The wide energy range of COSY leads to momenta of
outgoing protons to be detected in a single meson production reaction between
300 and 2500 MeV/c. Scattering angles of protons to be covered extend to about
in the laboratory system. An azimuthal angular coverage of the
device around 98% seems technically achievable. The required magnetic
spectrometer could consist of a superconducting toroid, providing fields around
3 T.Comment: 6 pages, 1 figure, submitted to Czechoslovak Journal of Physic
Measurements of X_2 and Other Results in the Analysis of d + 58-Ni Elastic Scattering
This work was supported by the National Science Foundation Grants NSF PHY 78-22774 A03, NSF PHY 81-14339, and by Indiana Universit
Initial singlet and triplet spin state contributions to pp -> pp pi0
The PINTEX facility at the IUCF Cooler ring, dedicated to the study of spin
dependence in nucleon-nucleon interactions, has been used to measure
polarization observables of the reaction pp -> pp pi0 at beam energies between
325 and 400 MeV. The stored polarized proton beam had spin projections both in
the longitudinal and the transverse directions with respect to the beam
momentum. We report here on the measurements of the relative transverse and
longitudinal spin-dependent cross sections, deltasigma_T/sigma_tot and
deltasigma_L/sigma_tot, and how from these observables the initial spin singlet
and triplet cross sections are obtained. Considering angular momentum states
less or equal to one, the contribution of the Ps partial waves to the cross
section can be extracted.Comment: Contribution to PANIC99, XVth Particles and Nuclei International
Conference, June 10-16, 1999, Uppsala, Sweden. Latex, 5 pages, 3 figure
Optical Model Analysis of Elastic Deuteron Scattering at 80 MeV
This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440
Analyzing Powers and Spin Correlation Coefficients for p+d Elastic Scattering at 135 and 200 MeV
The proton and deuteron analyzing powers and 10 of the possible 12 spin
correlation coefficients have been measured for p+d elastic scattering at
proton bombarding energies of 135 and 200 MeV. The results are compared with
Faddeev calculations using two different NN potentials. The qualitative
features of the extensive data set on the spin dependence in p+d elastic
scattering over a wide range of angles presented here are remarkably well
explained by two-nucleon force predictions without inclusion of a three-nucleon
force. The remaining discrepancies are, in general, not alleviated when
theoretical three-nucleon forces are included in the calculations.Comment: 43 pages, 12 figures, accepted for publication by Phys. Rev.
- …