Speaker
Description
PIONEER is a rare pion decay experiment that will run at the Paul Scherrer Institute (PSI) in Switzerland. In its initial phase, the primary objective is to significantly improve the measurement of the pion leptonic decay branching ratio:
$R_{e/\mu} = \mathcal{B}(\pi \to e\nu(\gamma)) / \mathcal{B}(\pi \to \mu\nu(\gamma))$. PIONEER aims to surpass the precision of the current best measurement, obtained by the PIENU experiment at TRIUMF, by more than an order of magnitude. This improvement would bring the experimental precision of $R_{e/\mu}$ to the $10^{-4}$ level, matching the accuracy of Standard Model calculations and providing a stringent test of lepton flavour universality.
To achieve this ambitious goal, PIONEER will exploit the world’s most intense pion beam at PSI, an active silicon-strip target based on Low Gain Avalanche Detectors (LGADs), and an optimized calorimeter geometry. This talk will present an overview of the experiment and its physics program, including searches for sterile neutrinos and tests of Cabibbo–Kobayashi–Maskawa matrix unitarity. It will also highlight recent detector R\&D activities for PIONEER, including LGAD beam tests performed at TRIUMF.
| Keyword-1 | Pion decay |
|---|---|
| Keyword-2 | Silicon strip target |