A team of physicists working in Italy on an experiment designed to detect dark matter, obtained data that suggest that they instead detected dark energy, something that is theorized, but has never yet been detected experimentally. This team discovered energy in excess of expected normal background gravitational interactions, and suspect that this excess is actually dark energy, which is considered to potentially be the “fifth force” in the universit
The results have been published in the open source journal Physical Review D.
Date: September 15, 2021
Title: “Direct detection of dark energy: The XENON1T excess and future prospects”
Authors: Sunny Vagnozzi, Luca Visinelli, Philippe Brax, Anne-Christine Davis, and Jeremy Sakstein
We explore the prospects for direct detection of dark energy by current and upcoming terrestrial dark matter direct detection experiments. If dark energy is driven by a new light degree of freedom coupled to matter and photons then dark energy quanta are predicted to be produced in the Sun. These quanta free-stream toward Earth where they can interact with Standard Model particles in the detection chambers of direct detection experiments, presenting the possibility that these experiments could be used to test dark energy. Screening mechanisms, which suppress fifth forces associated with new light particles, and are a necessary feature of many dark energy models, prevent production processes from occurring in the core of the Sun, and similarly, in the cores of red giant, horizontal branch, and white dwarf stars. Instead, the coupling of dark energy to photons leads to production in the strong magnetic field of the solar tachocline via a mechanism analogous to the Primakoff process. This then allows for detectable signals on Earth while evading the strong constraints that would typically result from stellar probes of new light particles. As an example, we examine whether the electron recoil excess recently reported by the XENON1T collaboration can be explained by chameleon-screened dark energy, and find that such a model is preferred over the background-only hypothesis at the 2.0σ level, in a large range of parameter space not excluded by stellar (or other) probes. This raises the tantalizing possibility that XENON1T may have achieved the first direct detection of dark energy. Finally, we study the prospects for confirming this scenario using planned future detectors such as XENONnT, PandaX-4T, and LUX-ZEPLIN.