Fine-grained binning in reconstructed di-neutrino mass q2_rec resolves narrow axion signals better than coarse binning or BDT axes, explaining the sensitivity gap and making the q2-based bound conservative.
The $B^+ \to K^+ \nu \bar \nu$ decay as a search for the QCD axion
4 Pith papers cite this work. Polarity classification is still indexing.
abstract
We introduce a model-independent framework to reinterpret Belle II results using only public data, analytically reconstructing the mapping between true and reconstructed kinematic variables within the statistically dominant Inclusive Tagging Analysis. This enables rare-decay measurements to probe light invisible particles -- such as the QCD axion or axion-like particles, collectively denoted $a$ -- without relying on internal simulations. Applying the method to $B^+ \! \to \! K^+ \nu \bar\nu$ yields the strongest bound on the branching fraction for $B^+ \! \to \! K^+ a$, improving existing limits by about a factor of nine and constraining the axion's fundamental flavour-changing coupling to $b$ and $s$ quarks. The approach establishes $B^+ \! \to \! K^+ \nu \bar\nu$ as a dual probe -- simultaneously testing short-distance new physics and light invisible states, the two probes working independently to an excellent approximation -- and provides a general strategy for model-independent reinterpretation of collider data.
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A single nearly degenerate dark matter multiplet in the MFV framework can accommodate either the K+ to pi+ nu nubar or B+ to K+ nu nubar excess but not both simultaneously.
Review surveying limits and prospects for flavor-violating decays of light axion-like particles, highlighting complementarity of lab, astro, and cosmo probes up to 10^12 GeV scales.
citing papers explorer
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The $B^+ \to K^+ \nu \bar \nu$ decay as a QCD axion search: comparing reinterpretation approaches
Fine-grained binning in reconstructed di-neutrino mass q2_rec resolves narrow axion signals better than coarse binning or BDT axes, explaining the sensitivity gap and making the q2-based bound conservative.
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Braking protons at the EIC: from invisible meson decay to new physics searches
The EIC can probe invisible pseudoscalar meson decays down to branching ratios of 10^{-8} and invisibly decaying ALPs with couplings up to 10^5 GeV for masses 0.1-2 GeV.
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Dark Matter emission at Belle II and NA62 in Minimal Flavor Violation framework
A single nearly degenerate dark matter multiplet in the MFV framework can accommodate either the K+ to pi+ nu nubar or B+ to K+ nu nubar excess but not both simultaneously.
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Flavor phenomenology of light dark particles
Review surveying limits and prospects for flavor-violating decays of light axion-like particles, highlighting complementarity of lab, astro, and cosmo probes up to 10^12 GeV scales.