Search for B+ => K+ nu nubar

Sumitted to PubDB: 2021-04-07

Category: Talk, Visibility: Public

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Authors	Filippo Dattola
Date	March 20, 2021
Belle II Number	BELLE2-TALK-CONF-2021-018
Abstract	A search for the flavour-changing neutral current decay B+ → K+ ν ν is performed with an electron-positron collision data sample corresponding to 63fb−1 collected at the Υ(4S) resonance by the Belle II experiment. A novel measurement method is developed, which exploits topological properties of the decay that differ from both generic bottom-meson decays and light-quark pair-production. This inclusive tagging approach has the benefit of a higher signal efficiency compared to previous searches for this rare decay. As no significant signal is observed, an upper limit on the branching fraction of B+ → K+ ν ν of 4.4 × 10−5 is set at the 90% confidence level.
Conference	Rencontres de Moriond 2021 - Electroweak Interactions & Unified Theories