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Near threshold eta meson production in the d+d->alpha+eta reaction

A. Wronska·V. Hejny·C. Wilkin·S. Dymov·C. Hanhart·V. Komarov·H. R. Koch·A. Kulikov·A. Magiera·T. Mersmann·S. Mikirtytchiants·H. Ohm·D. Prasuhn·R. Schleichert·H. J. Stein·H. Stroeher
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Abstract

The d+d->alpha+eta reaction has been investigated near threshold using the ANKE facility at COSY-Juelich. Both total and differential cross sections have been measured at two excess energies, Q=2.6 MeV and 7.7 MeV, with a subthreshold measurement being undertaken at Q=-2.6 MeV to study the physical background. While consistent with isotropy at the lower energy, the angular distribution reveals a pronounced anisotropy at the higher one, indicating the presence of higher partial waves. Options for the decomposition into partial amplitudes and their consequences for determination of the s-wave eta-alpha scattering length are discussed.

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A. Wronska, V. Hejny, C. Wilkin, S. Dymov, C. Hanhart, V. Komarov, H. R. Koch, A. Kulikov, A. Magiera, T. Mersmann, S. Mikirtytchiants, H. Ohm, D. Prasuhn, R. Schleichert, H. J. Stein, H. Stroeher. 2006-02-01. Near threshold eta meson production in the d+d->alpha+eta reaction. https://doi.org/10.1140/epja%2Fi2005-10185-0

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