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The analysis of high-precision π ± p → π ± p cross section data from the EPECUR Collaboration based on the multichannel K-matrix approach is presented. The sharp structures seen in these data are studied in terms of both opening thresholds and new resonance contributions. Some prominent features are found to be due to the opening KΣ channel. However, a complete description of the data is improved with the addition of two narrow resonant structures at W ∼ 1.686 and W ∼ 1.720 GeV. These structures are interpreted as manifestations of S11 and P11 resonances. The underlying nature of the observed phenomena is discussed.

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The analyzing power for proton-carbon elastic scattering in the Coulomb-nuclear interference region of momentum transfer, 9.0x10(-3)<-t<4.1x10(-2) (GeV/c)(2), was measured with a 21.7 GeV/c polarized proton beam at the Alternating Gradient Synchrotron of Brookhaven National Laboratory. The ratio of hadronic spin-flip to nonflip amplitude, r(5), was obtained from the analyzing power to be Rer(5)=0.088+/-0.058 and Imr(5)=-0.161+/-0.226.

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