Phys. Rev. D 108, L111104 (2023)

ISSN: 2470-0010, SCIE

Search for a long-lived spin-0 mediator in b → s transitions at the Belle II experiment

Belle II Collaboration (I. Adachi, ..., N. Anh Ky, ...)

Additional spin-0 particles appear in many extensions of the standard model. We search for long-lived spin-0 particles S in B-meson decays mediated by a b → s quark transition in eþe− collisions at the ϒð4SÞ resonance at the Belle II experiment. Based on a sample corresponding to an integrated luminosity of 189 fb−1, we observe no evidence for signal. We set model-independent upper limits on the product of branching fractions BðB0 → Kð892Þ0ð→ Kþπ−ÞSÞ × BðS → xþx−Þ and BðBþ → KþSÞ × BðS → xþx−Þ, where xþx− indicates eþe−; μþμ−; πþπ−, or KþK−, as functions of S mass and lifetime at the level of 10−7.

DOI: 10.1103/PhysRevD.108.L111104

Download: