From: H LV A beam of electrons should bend downward in earths gravity. Has that ever been measured?
Experiments to determine the Force of Gravity on Single Electrons and Positrons • FRED C. WITTEBORN • & WILLIAM M. FAIRBANK • Nature volume 220, pages 436–440 (02 November 1968) My comment. Behind a paywall - but the consensus seems to be this: the experiment partially but not fully supports the generally held view that gravity affects the electron or positron. Mills would say it is a poor experiment and not proof.