Beam particle tracking with a low-mass mini time projection chamber in the PEN experiment

C. J. Glaser, D. Pocanic, A. van der Schaaf +4

The international PEN collaboration aims to obtain the branching ratio for the pion electronic decay ${\pi }^{+}\to e^{+}{\nu }_e(\gamma )$, aka ${\pi }_{e2}$, to a relative precision of $5\times 10^{-4}$…