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The reaction anti-proton + proton -> anti-\Lambda + \Lambda -> anti-proton + \pi^+ + proton + \pi^- has been measured with high statistics at anti-proton beam momentum of 1.637 GeV/c. The use of a transversely-polarized frozen-spin target combined with the self-analyzing property of \Lambda/anti-\Lambda decay allows access to unprecedented information on the spin structure of the interaction. The most general spin-scattering matrix can be written in terms of eleven real parameters for each bin of scattering angle, each of these parameters is determined with reasonable precision. From these results all conceivable spin-correlations are determined with inherent self-consistency. Good agreement is found with the few previously existing measurements of spin observables in anti-proton + proton -> anti-\Lambda + \Lambda near this energy. Existing theoretical models do not give good predictions for those spin-observables that had not been previously measured. The reaction anti-proton + proton -> anti-\Lambda + \Lambda -> anti-proton + \pi^+ + proton + \pi^- has been measured with high statistics at anti-proton beam momentum of 1.637 GeV/c. The use of a transversely-polarized frozen-spin target combined with the self-analyzing property of \Lambda/anti-\Lambda decay allows access to unprecedented information on the spin structure of the interaction. The most general spin-scattering matrix can be written in terms of eleven real parameters for each bin of scattering angle, each of these parameters is determined with reasonable precision. From these results all conceivable spin-correlations are determined with inherent self-consistency. Good agreement is found with the few previously existing measurements of spin observables in anti-proton + proton -> anti-\Lambda + \Lambda near this energy. Existing theoretical models do not give good predictions for those spin-observables that had not been previously measured.

The reaction anti-proton + proton -> anti-��+ ��-> anti-proton + ��^+ + proton + ��^- has been measured with high statistics at anti-proton beam momentum of 1.637 GeV/c. The use of a transversely-polarized frozen-spin target combined with the self-analyzing property of ��/anti-��decay allows access to unprecedented information on the spin structure of the interaction. The most general spin-scattering matrix can be written in terms of eleven real parameters for each bin of scattering angle, each of these parameters is determined with reasonable precision. From these results all conceivable spin-correlations are determined with inherent self-consistency. Good agreement is found with the few previously existing measurements of spin observables in anti-proton + proton -> anti-��+ ��near this energy. Existing theoretical models do not give good predictions for those spin-observables that had not been previously measured., To be published in Phys. Rev. C. Tables of results (i.e. Ref. 24) are available at http://www-meg.phys.cmu.edu/~bquinn/ps185_pub/results.tab 24 pages, 16 figures

Spin-transfer observables for pp to Lambda Lambda have been measured using a transversely polarized frozen-spin target and a beam momentum of 1.637 GeV/c. Current models of the reaction near threshold are in good agreement with existing measurements performed with unpolarized particles in the initial state but produce conflicting predictions for the spin-transfer observables D/sub nn/ and K/sub nn/ (the normal-to-normal depolarization and polarization transfer), which are measurable only with polarized target or beam. Measurements of D/sub nn/ and K/sub nn/ presented here are found to be in disagreement with predictions from these models. (21 refs). Spin transfer observables for the strangeness-production reaction Antiproton-Proton -> Antilambda-Lambda have been measured by the PS185 collaboration using a transversely-polarized frozen-spin target with an antiproton beam momentum of 1.637 GeV/c at the Low Energy Antiproton Ring at CERN. This measurement investigates observables for which current models of the reaction near threshold make significantly differing predictions. Those models are in good agreement with existing measurements performed with unpolarized particles in the initial state. Theoretical attention has focused on the fact that these models produce conflicting predictions for the spin-transfer observables D_{nn} and K_{nn}, which are measurable only with polarized target or beam. Results presented here for D_{nn} and K_{nn} are found to be in disagreement with predictions from existing models. These results also underscore the importance of singlet-state production at backward angles, while current models predict complete or near-complete triplet-state dominance.

The PS185 experiment at LEAR/CERN has investigated strangeness production in antiproton-proton collisions with final states such as $\overline�� ��$, $\overline��^0 ��+ c.c$, $\overline{��^+} ��^+$, $\overline{��^-} ��^-$ and $K_S K_S$. Results are presented from a study of about 32,000 {$K_S K_S X$} events obtained at several antiproton momenta in the regions of 1.45 and 1.7 GeV/c. The $\overline{p} p \to K_S K_S ��$ cross sections extracted at these momenta constitute the first measurement of this reaction in flight and are broadly consistent with expectations of a phase-space extrapolation of branching ratios from annihilation at rest., 10 pages, 6 figures, LaTeX, less figures to save space, adapted text

The muon anomalous magnetic moment has been measured in a new experiment at Brookhaven. Polarized muons were stored in a superferric ring, and the angular frequency difference, omega(a), between the spin precession and orbital frequencies was determined by measuring the time distribution of high-energy decay positrons. The ratio R of omega(a) to the Larmor precession frequency of free protons, omega(p), in the storage-ring magnetic field was measured. We find R = 3.707 220(48) X 10(-3). With mu(mu)/mu(p) = 3.183 345 47(47) this gives a(mu+) = 1 165 925(15) X 10(-9) (+/-13 ppm), in good agreement with the previous CERN measurements for mu(+) and mu(-) and of approximately the same precision.