Searches for dark sector particles at Belle and Belle II

Sumitted to PubDB: 2025-05-09

Category: Talk, Visibility: Latest Version Public

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Authors	Haruki Kindo
Date	2025-05-09
Belle II Number	BELLE2-TALK-2025-070
Abstract	The Belle and Belle II experiment have collected samples of $e^+e^-$ collision data at centre-of-mass energies near the $\Upsilon(nS)$ resonances. These data have constrained kinematics and low multiplicity, which allow searches for dark sector particles in the mass range from a few MeV to 10 GeV. Using a 426 fb$^{-1}$ sample collected by Belle II, we search for inelastic dark matter accompanied by a dark Higgs. Using a 711 fb$^{-1}$ sample collected by Belle, we search for $B\to h + \mathrm{invisible}$ decays, where $h$ is a $\pi$, $K$, $D$, $D_{s}$ or $p$, and $B\to Ka$, where $a$ is an axion-like particle.