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arXiv · 1911.03490

Probing dark sectors with long-lived particles at BELLE II

Anastasiia Filimonova·Ruth Schäfer·Susanne Westhoff
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Abstract

We propose a new search for light scalar singlets in rare meson decays. For tiny interactions, the scalar is long-lived at detector scales and decays into displaced pairs of leptons or light mesons. We show that Belle II has a remarkable potential to probe scalars in the GeV range with couplings as small as $10^{-5}$. The predicted sensitivity is higher than at the long-baseline experiments FASER and NA62. We also investigate signatures of invisibly decaying scalars in rare meson decays with missing energy.

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Anastasiia Filimonova, Ruth Schäfer, Susanne Westhoff. 2019-11-08. Probing dark sectors with long-lived particles at BELLE II. https://doi.org/10.1103/physrevd.101.095006

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