CHASE Update


Not long ago the Chameleon Afterglow Search (CHASE) reported its results on a search for a candidate dark energy particle. While those results did not report a “chameleon” afterglow signal, it did report an afterglow signal—the “orange glow”. A significant amount of additional data was taken to characterize this orange glow, its color, temperature dependence, time dependence, magnetic field dependence, and polarization dependence. While the orange glow itself is likely due to fluorescence in some of the vacuum materials, knowledge of its presence will be a useful guide in the design of future experiments. The plot shown gives the time dependence of the orange glow with three fitted models—a single exponential model (green dotted), a model with a direct decay and self-interaction decay (blue dashed), and a preferred model with both (black solid). These results will soon appear in Physical Review D.

– Jason Steffen