# ICHEP2018 SEOUL

Jul 4 – 11, 2018
COEX, SEOUL
Asia/Seoul timezone

## Improved studies of B—>D(*) tau nu with vertexing at Belle II

Jul 7, 2018, 2:45 PM
15m
203 (COEX, Seoul)

### 203

#### COEX, Seoul

Parallel Beyond the Standard Model

### Speaker

Abi Soffer (Tel Aviv University (IL))

### Description

BABAR, Belle, and LHCb measure the rates for the decays $B \to D^{(*)} \tau \nu$ and $B_c\to J/\psi \tau \nu$ to be higher than the SM expectations, with a combined discrepancy of $4.1 \sigma$ (for $B \to D^{(*)} \tau \nu$ only) or $\sim 4.3 \sigma$ (including all modes). In the coming years, Belle II and LHCb will greatly improve the measurement precision, to the level that systematic uncertainties associated with the background $B \to D^{**} \ell \nu$ become critical. We show how to utilize Belle II's high spatial resolution to obtain a model-independent handle on this background and improve the overall signal-backgroud. We also study the impact of vertexing on Belle II’s capability to perform this measurement with the decay $\tau \to 3 \pi \nu$, as already demonstrated by LHCb.

### Primary authors

Ida Peruzzi (Laboratori Nazionali di Frascati dell'INFN) Abi Soffer (Tel Aviv University (IL))