First Observation of $\hat{I}›$ Hyperon Transverse Polarization in $\ddot{I}ˆ(3686)\to \hat{I}›\bar{\hat{I}}›$

BESIII Collaboration, M. Ablikim, M. N. Achasov +687

Based on $(448.1\pm 2.9)\times 10^6$ $\ddot{I}ˆ(3686)$ events collected with the BESIII detector at the BEPCII collider, we present the first observation of spin transverse polarization o…