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A new experiment to search for the invisible decay of the orthopositronium

A. Badertscher·P. Crivelli·W. Fetscher·S. N. Gninenko·J. P. Peigneux·A. Rubbia·D. Sillou
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Abstract

We propose an experiment to search for invisible decays of orthopositronium (o-Ps) with a 90% confidence sensitivity in the branching ratio as low as $10^{-8}$. Evidence for this decay mode would unambigously signal new physics: either the existence of extra--dimensions or fractionally charged particles or new light gauge bosons. The experimental approach and the detector components of the proposed experiment are described.

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A. Badertscher, P. Crivelli, W. Fetscher, S. N. Gninenko, J. P. Peigneux, A. Rubbia, D. Sillou. 2004-04-28. A new experiment to search for the invisible decay of the orthopositronium. https://arxiv.org/abs/hep-ex/0404037

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