Collaborative Research: NSF-BSF: Continuation of the XENON Program at LNGS

Data from the XENONnT Dark Matter Experiment in the Gran Sasso Underground Laboratory

This proposal in focused on the XENONnT Dark Matter detector, being built in the Gran Sasso Underground Laboratory in Italy. This is a collaborative effort to build and run the most sensitive Dark Matter detector world—wide, which is expected to give its full results after four years of running and taking data.

The XENONnT experiment is centered around a target mass of 8.5 t of liquefied xenon gas, held at a temperature of about —100°C, and instrumented with light sensors and electric fields. This setup, callec a Time Projection Chamber, allows the discovery of interactions inside the xenon, either with radioactive radiation such as at, H,'y or neutrons, or with potential dark matter particle candidates and some rare types of radiation such as neutrinos.

The experiment, currently under construction, will run and take data for about four year net, and will perform studies and calibrations searching for various physics channels. The channels we will focus on include: Search for Dark Matter particles interacting with xenon nuclei, different interpretations of this ( ata, interactions of hidden particles with electrons — particles arriving from the Sun or the Galaxy, changes in time of the rate of events, searching for extra-terrestrial source of measured radiation and others. We will perform dedicated high accuracy calibrations of the experiment in order to characterize the response to different types of radiation and events and quantify the backgrounds which may accompany a signal of interest.

While the full exposure of the experiment is only expected after about four years, there will be interim data to be analyzed and published, with new records of sensitivity in many channels expected by the end of the second year.