Making most of Belle II’s B decays with invisible signatures

by Slavomira Stefkova (PI)

Thursday 11 Dec 2025, 10:00 → 12:00 Europe/Berlin

Käthe-Kümmel-Str. 1/U1.059 (ROT) - Conference Room (ROT)

Abstract: 

The decay B+→K+νν̄ is a rare process mediated by a flavor-changing neutral current, providing a powerful probe for New Physics (NP) beyond the Standard Model (SM). The SM predicts a branching fraction of approximately 6×10−6, while various NP scenarios, including those involving dark matter candidates, anticipate significant enhancements. The most recent Belle II measurement observed a 4.6-fold enhancement of the rate with respect to SM with compatibility of  ‘only’ 2.7σ.
In this seminar, I will present key aspects of this experimentally challenging measurement, highlighting the innovative techniques developed to suppress background and enhance signal efficiency. Additionally, I will introduce a novel approach to responsibly reinterpret such measurements under varying kinematic assumptions for the signal. Finally, I discuss the future prospects of this “golden channel” and explore its complementarity with other B-meson decays featuring similar invisible signatures.

 

 

Join Zoom Meeting
https://uni-bonn.zoom-x.de/j/66253567797?pwd=R2MrNmNCQnl4K1hSejd6VnBEYXJ2QT09

Meeting ID: 662 5356 7797
Passcode: 599591