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arXiv · 2507.17286

Searches for hidden sectors using $K^+\to\pi^+X$ decays

NA62 Collaboration
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Abstract

Results from the study of the rare decays $K^+\to\pi^+\nu\bar{\nu}$, $K^{+}\rightarrow\pi^{+}\mu^{+}\mu^{-}$ and $K^{+}\rightarrow\pi^{+}\gamma\gamma$ at the NA62 experiment at CERN are interpreted in terms of improved limits for $\rm{B}(K^+\to\pi^+X)$ and coupling parameters of hidden-sector models, where $X$ is a mediator. World-leading limits are achieved for dark photon, dark scalar and axion-like particle models.

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NA62 Collaboration. 2025-07-23. Searches for hidden sectors using $K^+\to\pi^+X$ decays. https://arxiv.org/abs/2507.17286

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