title: Search for free fractional electric charge elementary particles using an automated millikan oil drop technique
abstract: We have carried out a direct search in bulk matter for free fractional electric charge elementary particles using the largest mass single sample ever studied-about 17.4 mg of silicone oil. The search used an improved and highly automated Millikan oil drop technique. No evidence for fractional charge particles was found. The concentration of particles with fractional charge more than 0. 16e ( e being the magnitude of the electron charge) from the nearest integer charge is less than 4.71x10(-22) particles per nucleon with 95% confidence.
authors.affiliation: Stanford Linear Accelerator Center, Stanford, California 94309, USA.
authors.initials: V
authors.lastname: Halyo
authors.initials: P
authors.lastname: Kim
authors.initials: ER
authors.lastname: Lee
authors.initials: IT
authors.lastname: Lee
authors.initials: D
authors.lastname: Loomba
authors.initials: ML
authors.lastname: Perl