Proton-helium elastic scattering: a possible high-energy polarimeter at RHIC-BNL
Abstract We examine a suggestion to use p- 4 He elastic scattering, as an absolute polarimeter for high-energy polarized proton beams, by means of a Coulomb-Nuclear Interference effect for the single-spin asymmetry A N ( t ), around the diffractive minimum of the differential cross section |t|∼0.21 GeV 2 . Although this reaction has a fairly simple dynamical structure, our theoretical uncertainties and the present experimental inaccuracy of the differential cross section in this t region, allows one to generate dramatic effects for A N ( t ), which will be discussed.
Spin-flip component of the pomeron
Abstract The spin-flip pomeron amplitude is estimated in the Born approximation of QCD using the nonrelativistic quark model for the nucleon wave function. A nonzero result is possible if the nucleon contains a dynamically enhanced component with a compact diquark. The proposed model-independent way of the pomeron spin-flip measurement in the Coulomb-nuclear interference region is now in progress in the experiment E-704 at the Fermilab TEVATRON.
MCNP(TM) Version 5.
The Monte Carlo transport workhorse, MCNP, is undergoing a massive renovation at Los Alamos National Laboratory (LANL) in support of the Eolus Project of the Advanced Simulation and Computing (ASCI) Program. MCNP Version 5 (V5) (expected to be released to RSICC in Spring, 2002) will consist of a major restructuring from FORTRAN-77 (with extensions) to ANSI-standard FORTRAN-90 with support for all of the features available in the present release (MCNP-4C2/4C3). To most users, the look-and-feel of MCNP will not change much except for the improvements (improved graphics, easier installation, better online documentation). For example, even with the major format change, full support for incremental patching will still be provided. In addition to the language and style updates, MCNP V5 will have various new user features. These include improved photon physics, neutral particle radiography, enhancements and additions to variance reduction methods, new source options, and improved parallelism support (PVM, MPI, OpenMP).