Today's View on Strangeness

There are several different experimental indications, such as the pion-nucleon sigma term and polarized deep-inelastic scattering, which suggest that the nucleon wave function contains a hidden s bar s component. This is expected in chiral soliton models, which also predicted the existence of new exotic baryons that may recently have been observed. Another hint of hidden strangeness in the nucleon is provided by copious phi production in various N bar N annihilation channels, which may be due to evasions of the Okubo-Zweig-Iizuka rule. One way to probe the possible polarization of hidden s bar s pairs in the nucleon may be via Lambda polarization in deep-inelastic scattering.Comment: 8 pages LaTeX, 10 figures, to appear in the Proceedings of the International Conference on Parity Violation and Hadronic Structure, Grenoble, June 200

New data on OZI rule violation in bar{p}p annihilation at rest

The results of a measurement of the ratio R = Y(phi pi+ pi-) / Y(omega pi+ pi-) for antiproton annihilation at rest in a gaseous and in a liquid hydrogen target are presented. It was found that the value of this ratio increases with the decreasing of the dipion mass, which demonstrates the difference in the phi and omega production mechanisms. An indication on the momentum transfer dependence of the apparent OZI rule violation for phi production from the 3S1 initial state was found.Comment: 11 pages, 3 PostScript figures, submitted to Physics Letter

DEVELOPMENT OF A CRYOGENIC SOURCE OF POLARIZED DEUTERONS "POLARIS"

Afin d'obtenir un faisceau de deutérons polarisés, une source cryogénique "Polaris" a été développée dans le cadre du programme de recherche du synchrophasotron de Dubna/1/. La source est raccordée à une borne haute-tension du préaccélérateur linac. Un faisceau de deutérons est accéléré dans le synchrophasotron/2/. Cette source est actuellement à l'essai. Un polarimètre à cibles 3He et 4He a été conçu afin de mesurer la polarisation du faisceau après le linac. Les résultats de ces mesures sont publiés dans ce rapport.To obtain a beam of polarized deuterons, a cryogenic source "Polaris" has been developed according to the program of research at the Dubna synchrophasotron/1/. The source is installed on a high-voltage terminal of the linac preaccelerator. A beam of deuterons from the source is accelerated in the synchrophasotron/2/. At present the source is being improved. A polarimeter with 3He and 4He targets has been developed to measure the polarization of the beam of deuterons after the linac. Results of this work are presented in the report