B. R. Heckel

Tests of the Gravitational Inverse-Square Law below the Dark-Energy Length Scale

We conducted three torsion-balance experiments to test the gravitational inverse-square law at separations between 9.53 mm and 55 microm, probing distances less than the dark-energy length scale lambda(d)=[4 -root](variant Plancks over 2pic/rho(d) approximately 85 microm. We find with 95% confidence that the inverse-square law holds (|alpha|<or=1) down to a length scale lambda=56 microm and that an extra dimension must have a size R<or=44 microm.

Submillimeter Test of the Gravitational Inverse-Square Law: A Search for “Large” Extra Dimensions

Motivated by higher-dimensional theories that predict new effects, we tested the gravitational 1/r(2) law at separations ranging down to 218 microm using a 10-fold symmetric torsion pendulum and a rotating 10-fold symmetric attractor. We improved previous short-range constraints by up to a factor of 1000 and find no deviations from Newtonian physics.

Sub-millimeter tests of the gravitational inverse-square law

Motivated by a variety of theories that predict new effects, we tested the gravitational

Improved limit on the permanent electric dipole moment of 199Hg.

{1/r}^{2}

New CP-Violation and Preferred-Frame Tests with Polarized Electrons

law at separations between 10.77 mm and

Apparatus for measurement of the electric dipole moment of the neutron using a cohabiting atomic-mercury magnetometer

137\ensuremath{\mu}\mathrm{m}

Torsion Balance Test of Spin Coupled Forces

using two different 10-fold azimuthally symmetric torsion pendulums and rotating 10-fold symmetric attractors. Our work improves upon other experiments by up to a factor of about 100. We found no deviation from Newtonian physics at the 95% confidence level and interpret these results as constraints on extensions of the standard model that predict Yukawa or power-law forces. We set a constraint on the largest single extra dimension (assuming toroidal compactification and that one extra dimension is significantly larger than all the others) of

Short-range spin-dependent interactions of electrons: a probe for exotic pseudo-Goldstone bosons

{R}_{*}l~160\ensuremath{\mu}\mathrm{m},

A liquid helium target system for a measurement of parity violation in neutron spin rotation

and on two equal-sized large extra dimensions of

A low-noise 3He ionization chamber for measuring the energy spectrum of a cold neutron beam

{R}_{*}l~130\ensuremath{\mu}\mathrm{m}.