Amol Upadhye

HEP Division

How dark is dark energy? A laboratory search for couplings between photons and chameleon dark energy

Dark energy can differ from the cosmological constant, the simplest model for the cosmic acceleration, either by evolving with time or by coupling to known particles. Coupled theories typically invoke a screening mechanism, such as the chameleon mechanism, to explain tight constraints on fifth forces and the evolution of fundamental constants locally. I will discuss the GammeV-CHASE experiment, conducted last year at Fermilab, which was designed to produce, trap, and detect photon-coupled chameleon dark energy. GammeV-CHASE has improved constraints on photon-chameleon couplings by orders of magnitude and has ruled out a range of models at the dark energy scale.

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