arXiv subjects

J. G. Lee

Publications and source records attributed to J. G. Lee.

4 recordsLinked to original sources

arXiv2021

A Low-Frequency Torsion Pendulum with Interferometric Readout

We describe a torsion pendulum with a large mass-quadrupole moment and a resonant frequency of 2.8 mHz, whose angle is measured using a modified Michelson interferometer. The system achieved noise levels of $\sim200\ \text{prad}/\sqrt{\text{Hz}}$ between 0.2-30 Hz and $\sim10\ \text{prad}/\sqrt{\text{Hz}}$ above 100 Hz. Such a system can be applied to a broad range of fields from the study of rotational seismic motion and elastogravity signals to gravitational wave observation and tests of gravity.

physics.ins-det↗

arXiv2020

Limits on the Stochastic Gravitational Wave Background and Prospects for Single Source Detection with GRACE Follow-On

With a reinterpretation of recent results, the GRACE Follow-On mission can be applied to gravitational wave astronomy. Existing GRACE Follow-On data constrain the stochastic gravitational wave background to $Ω_{GW}<3.3\times10^{7}$ at 100 mHz. With a dedicated analysis, GRACE Follow-On may be able to detect the inspiral of local neutron star binaries, inspiral of subgalactic stellar-mass black hole binaries, or mergers of intermediate-mass black hole binaries within the Milky Way.

gr-qc↗

arXiv2020

New Test of the Gravitational $1/r^2$ Law at Separations down to 52 $μ$m

We tested the gravitational $1/r^2$ law using a stationary torsion-balance detector and a rotating attractor containing test bodies with both 18-fold and 120-fold azimuthal symmetries that simultaneously tests the $1/r^2$ law at two different length scales. We took data at detector-attractor separations between $52~μ$m and 3.0 mm. Newtonian gravity gave an excellent fit to our data, limiting with 95\% confidence any gravitational-strength Yukawa interactions to ranges $< 38.6~μ$m.

hep-ex↗

arXiv2015

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

We used a torsion pendulum and rotating attractor with 20-pole electron-spin distributions to probe dipole-dipole interactions mediated by exotic pseudo-Goldstone bosons with $m_{\rm b}\leq 500 \; μ$eV and coupling strengths up to 14 orders of magnitude weaker than electromagnetism. This corresponds to symmetry-breaking scales $F \leq 70$ TeV, the highest reached in any laboratory experiment. We used an attractor with a 20-pole unpolarized mass distribution to improve laboratory bounds on $CP$-violating monopole-dipole interactions with $1.5\:μ$eV$<m_{\rm b}<400\:μ$eV by a factor of up to 1000.

hep-ex↗