AMPLITUDE ANALYSIS OF REACTIONS π−p → ηπ−p AND π−p → ηπn MEASURED ON POLARIZED TARGET AND THE EXOTIC 1−+ MESON

Recently several experimental groups analysed data on πp → ηπp and πp → ηπn reactions with exotic 1 P -wave and found a conflicting evidence for an exotic meson I = 11(1405). High statistics data on these reactions are presently analysed by BNL E852 Collaboration. All these analyses are based on the crucial assumption that the production amplitudes do not depend on nucleon spin. This assumption is in sharp conflict with the results of measurements of πp → ππn, πn → ππp and Kn → Kπp on polarized targets at CERN which find a strong dependence of production amplitudes on nucleon spin. To ascertain the existence of exotic meson 1(1405), it is necessary to perform a model-independent amplitude analysis of reactions πp → ηπp and πp → ηπn. We demonstrate that measurements of these reactions on transversely polarized targets enable the required model independent amplitude analysis without the assumption that producelectronic address: [email protected]