999 research outputs found
Parity Violation and the Nucleon-Nucleon System
The status of the field of nuclear parity violation---both experimental and
theoretical---is reviewed, with special emphasis on those results which have
been obtained since the 1985 review article by Adelberger and Haxton.Comment: 52 page standard Latex file, contribution to the volume "Symmetries
in Nuclear Physics," ed. W.C. Haxton and E. Henle
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.
Parity violation in deuteron photo-disintegration
We analyze the energy dependence for two types of parity-non-conserving
(PNC) asymmetries in the reaction in the near-threshold
region. The first one is the asymmetry in reaction with circularly polarized
photon beam and unpolarized deuteron target. The second one corresponds to
those with an unpolarized photon beam and polarized target. We find that the
two asymmetries have quite different energy dependence, and their shapes are
sensitive to the PNC-meson exchange coupling constants.
The predictions for the future possible experiments to provide definite
constraints for the PNC-coupling constants are discussed.Comment: 22 pages, 12 figures. Submitted to Phys.Rev.C 10Oct.0
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
Dependence of pp->pp pi0 near Threshold on the Spin of the Colliding Nucleons
A polarized internal atomic hydrogen target and a stored, polarized beam are
used to measure the spin-dependent total cross section Delta_sigma_T/sigma_tot,
as well as the polar integrals of the spin correlation coefficient combination
A_xx-A_yy, and the analyzing power A_y for pp-> pp pi0 at four bombarding
energies between 325 and 400 MeV. This experiment is made possible by the use
of a cooled beam in a storage ring. The polarization observables are used to
study the contribution from individual partial waves.Comment: 6 pages, 1 table, 4 figures, corrected equations 2 and
Reanalysis of multi-temporal aerial images of Storglaciären, Sweden (1959–99) – Part 1: Determination of length, area, and volume changes
Storglaciären, located in the Kebnekaise massif in northern Sweden, has a long history of glaciological research. Early photo documentations date back to the late 19th century. Measurements of front position variations and distributed mass balance have been carried out since 1910 and 1945/46, respectively. In addition to these in-situ measurements, aerial photographs have been taken at decadal intervals since the beginning of the mass balance monitoring program and were used to produce topographic glacier maps. Inaccuracies in the maps were a challenge to early attempts to derive glacier volume changes and resulted in major differences when compared to the direct glaciological mass balances. In this study, we reanalyzed dia-positives of the original aerial photographs of 1959, -69, -80, -90 and -99 based on consistent photogrammetric processing. From the resulting digital elevation models and orthophotos, changes in length, area, and volume of Storglaciären were computed between the survey years, including an assessment of related errors. Between 1959 and 1999, Storglaciären lost an ice volume of 19×106 m3, which corresponds to a cumulative ice thickness loss of 5.69 m and a mean annual loss of 0.14 m. This ice loss resulted largely from a strong volume loss during the period 1959–80 and was partly compensated during the period 1980–99. As a consequence, the glacier shows a strong retreat in the 1960s, a slowing in the 1970s, and pseudo-stationary conditions in the 1980s and 1990s
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