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arXiv · 0812.4187

Search for $\eta$-mesic nuclei in recoil-free transfer reaction

GEM Collaboration·A. Budzanowski
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Abstract

We have studied the reaction $p+{^{27}Al}\to {^3{He}}+p+\pi^-+X$ at recoil-free kinematics. An $\eta$ meson possibly produced in this reaction would be thus almost at rest in the laboratory system and could therefore be bound with high probability, if nuclear $\eta$ states exist. The decay of such a state through the $N^*(1535)$ resonance would lead to a proton-$\pi^-$ pair emitted in opposite directions. For these conditions we find some indication of such a bound state. An upper limit of $\approx$ 0.5 nb is found.

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GEM Collaboration, A. Budzanowski. 2008-12-22. Search for $\eta$-mesic nuclei in recoil-free transfer reaction. https://doi.org/10.1103/physrevc.79.012201

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