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arXiv · 0906.1946

The study of the negative pion production in neutron-proton collisions at beam momenta below 1.8 GeV/c

V. V. Sarantsev·K. N. Ermakov·L. M. Kochenda·V. I. Medvedev·V. A. Nikonov·O. V. Rogachevsky·A. V. Sarantsev·S. G. Sherman·V. A. Trofimov·A. A. Vasiliev
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Abstract

A detailed investigation of the reaction np -> pp\pi^{-} has been carried out using the data obtained with the continuous neutron beam produced by charge exchange scattering of protons off a deuterium target. A partial wave event-by-event based maximum likelihood analysis was applied to determine contributions of different partial waves to the pion production process. The combined analysis of the np -> pp\pi^{-} and pp -> pp\pi^{0} data measured in the same energy region allows us to determine the contribution of isoscalar partial waves (I=0) in the momentum range from 1.1 up to 1.8 GeV/c. The decay of isoscalar partial waves into (^1S_0)_{pp}\pi$ channel provides a good tool for a determination of the pp S-wave scalar scattering length in the final state which was found to be a_{pp}=-7.5\pm 0.3 fm.

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V. V. Sarantsev, K. N. Ermakov, L. M. Kochenda, V. I. Medvedev, V. A. Nikonov, O. V. Rogachevsky, A. V. Sarantsev, S. G. Sherman, V. A. Trofimov, A. A. Vasiliev. 2009-06-10. The study of the negative pion production in neutron-proton collisions at beam momenta below 1.8 GeV/c. https://doi.org/10.1140/epja/i2009-10891-5

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