5 research outputs found
Spin dependence of the antinucleon-nucleon interaction
The status of our present knowledge on the antinucleon-nucleon interaction at
low and medium energies is discussed. Special emphasis is put on aspects
related to its spin dependence which are relevant for experiments planned by
the PAX collaboration. Predictions for the spin-dependent antiproton-proton
cross sections sigma_1 and sigma_2 are presented, utilizing antinucleon-nucleon
potential models developed by the Juelich group, and compared to results based
on the amplitudes of the Nijmegen partial-wave analysis.Comment: 8 pages, 4 figures, to appear in the proceedings of the 19th
International Spin Physics Symposium, September 27 - October 2, 2010,
Juelich, German
Spin-dependent pbar-d cross sections at low and intermediate energies
Antiproton-deuteron () scattering is calculated at beam energies
below 300 MeV within the Glauber approach, utilizing the amplitudes of the
J\"ulich models. A good agreement is obtained with available
experimental data on upolarized differential and integrated cross
sections. Predictions for polarized total cross sections are
presented, obtained within the single scattering approximation including
Coulomb-nuclear interference effects. It is found that the total longitudinal
and transversal cross sections are comparable in absolute value to
those for scattering.
The kinetics of polarization buildup is considered.Comment: 8 pages, 5 figures, to appear in proceedings of the 19th
international Spin Physics Symposium, September 27 - October 2, 2010,
Juelich, German
Measurement of the Spin-Dependence of the pbar-p Interaction at the AD-Ring
We propose to use an internal polarized hydrogen storage cell gas target in
the AD ring to determine for the first time the two total spin-dependent pbar-p
cross sections sigma_1 and sigma_2 at antiproton beam energies in the range
from 50 to 450 MeV. The data obtained are of interest by themselves for the
general theory of pbar-p interactions since they will provide a first
experimental constraint of the spin-spin dependence of the nucleon-antinucleon
potential in the energy range of interest. In addition, measurements of the
polarization buildup of stored antiprotons are required to define the optimum
parameters of a future, dedicated Antiproton Polarizer Ring (APR), intended to
feed a double-polarized asymmetric pbar-p collider with polarized antiprotons.
Such a machine has recently been proposed by the PAX collaboration for the new
Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt, Germany.
The availability of an intense stored beam of polarized antiprotons will
provide access to a wealth of single- and double-spin observables, thereby
opening a new window on QCD spin physics.Comment: 51 pages, 23 figures, proposal submitted to the SPS committee of CER