title: New constraints on short-range forces coupling mass to intrinsic spin.
abstract: A new device that we refer to as the spherical superconducting torsion balance has been used to search for a new force coupling mass to intrinsic spin. Our experimental approach also employs a novel spin-source geometry that allows unprecedented sensitivity in the range 100 mum<lambda<5 mm. We place new limits on the dimensionless coupling constant of such an interaction of g_{p};{e}g_{s}<(-1.9+/-(1.3)_{stat}+/-(1.5)_{syst})x10;{-26} for lambda>10 mm at 1sigma confidence. At a range of 1 mm our most relaxed limit is g_{p};{e}g_{s}<1.5x10;{-24}.
authors.affiliation: School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
authors.forename: Giles D
authors.initials: GD
authors.lastname: Hammond
authors.forename: Clive C
authors.initials: CC
authors.lastname: Speake
authors.forename: Christian
authors.initials: C
authors.lastname: Trenkel
authors.forename: Antonio Pulido
authors.initials: AP
authors.lastname: Patón