​4:00 PM  (CET) 27 October 2020. Prof. Dr. ANDREW GERACI (Northwestern University)

Searching for “Fifth-forces”, Dark Matter, and Quantum Gravity in the Lab

We normally think of large accelerators and massive detectors when we consider the frontiers of elementary particle physics, pushing to understand the universe at higher and higher energy scales. However, several tabletop low-energy experiments are positioned to discover a wide range of new physics beyond the Standard model of particle physics, where feeble interactions require precision measurements rather than high energies.  In high vacuum, optically-levitated dielectric nanospheres achieve excellent decoupling from their environment, making force sensing at the zeptonewton level (10-21 N) achievable.  In this talk I will describe our progress towards using these sensors for tests of the Newtonian gravitational inverse square law at micron length scales and the Casimir Force.  Optically levitated dielectric objects and show promise for a variety of other applications, including searches for gravitational waves and Dark Matter.  Cooling these objects into the quantum regime of their motion paves the way for tests of quantum coherence in macroscopic objects and tests of whether gravity can destroy such coherence. Looking forward, these systems may enable us to examine the role that gravity plays in quantum mechanical entanglement.