Abstract
Differential and total cross sections for eta-meson production in the reaction π − p → ηn were measured within the experimental program eta-meson physics implemented in the pion channel of the synchrocyclotron of the Petersburg Nuclear Physics Institute (PNPI, Gatchina). These measurements were performed at incident-pion momenta (700, 710, 720, and 730 MeV/c) in the vicinity of the threshold for the process under study by using the neutral-meson spectrometer designed and created at the Meson Physics Laboratory of PNPI. It is shown that, in the immediate vicinity of the threshold (685 MeV/c), the process of eta-meson production proceeds predominantly via S 11(1535)-resonance formation followed by the decay S 11(1535) → ηn (the respective branching fraction is Br ≈ 60%), but that, as the momentum of incident pions increases, the role of the D wave becomes ever more important. A detailed analysis of this effect indicates that it is due to the increasing contribution of the D 13(1520) resonance. Although the branching fraction of the decay of this resonance through the ηn channel is assumed to be very small (BR ≈ 0.24%), the effect is enhanced owing to the interference between the D wave and the dominant resonance S 11(1535).
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References
B. L. Birbrair and A. B. Gridnev, Z. Phys. A 354, 95 (1996).
D. E. Bayadilov et al., Preprint No. 2612, PIYad. Fiz. (Petersburg Nucl. Phys. Inst., Gatchina, 2005).
S. Prakhov et al., Phys. Rev. C 69, 045202 (2004).
V. P. Koptev et al., Preprint No. 196, LIYad. Fiz. (Leningrad Nucl. Fiz. Inst., Leningrad, 1975).
S. Prakhov et al., Phys. Rev. C 72, 015203 (2005).
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Original Russian Text © D.E. Bayadilov, Yu.A. Beloglazov, A.B. Gridnev, N.G. Kozlenko, S.P. Kruglov, A.A.Kulbardis, I.V. Lopatin, D.V. Novinskiy, A.K. Radkov, V.V. Sumachev, E.A. Filimonov, A.V. Shvedchikov, 2012, published in Yadernaya Fizika, 2012, Vol. 75, No. 8, pp. 982–991.
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Bayadilov, D.E., Beloglazov, Y.A., Gridnev, A.B. et al. Investigation of near-threshold eta-meson production in the reaction π − p→ ηn . Phys. Atom. Nuclei 75, 923–932 (2012). https://doi.org/10.1134/S1063778812080042
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DOI: https://doi.org/10.1134/S1063778812080042