Search for Millicharged Particles Using Optically Levitated Microspheres

Abstract

We report results from a search for stable particles with charge > $10^{-5}$ e in bulk matter using levitated dielectric microspheres in high vacuum. No evidence for such particles was found in a total sample of 1.4 ng, providing an upper limit on the abundance per nucleon of 2.5 x $10^{-14}$ at the 95% confidence level for the material tested. These results provide the first direct search for single particles with charge < 0.1 e bound in macroscopic quantities of matter and demonstrate the ability to perform sensitive force measurements using optically levitated microspheres in vacuum.

Published version. 5 pages, 4 figures

References in corpus (4)

• Millikelvin cooling of an optically trapped microsphere in vacuum
• Turning off the Lights: How Dark is Dark Matter?
• An Improved Limit on Invisible Decays of Positronium
• Search for millicharged particles in reactor neutrino experiments: a probe of the PVLAS anomaly

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• Constraints on Spatially Oscillating Sub-mm Forces from the Stanford Levitated Microsphere Experiment Data
• Single and two-mode mechanical squeezing of an optically levitated nanodiamond via dressed-state coherence
• Probing millicharged particles with ultrasensitive optical nonlinear sensor based on levitated cavity optomechanics