Session H17: WIMP Dark Matter II

Towards the Gravitational Detection of Dark Matter on Earth

Current experimental efforts to see particulate dark matter rely upon the assumption of a non-gravitational interaction with visible matter. Here, we propose an approach for the direct detection of dark matter through its gravitational coupling to terrestrial devices. Relying upon advances in mechanical systems and their detection, we propose that an array of high-quality factor, massive mechanical resonators can detect the tiny classical gravitational forces induced by individual dark matter particles passing through the detector. With current technology and relatively standard assumptions about the distribution of dark matter in our galaxy, we estimate that it is possible to measure Planck-scale dark matter particles. With simple improvements to the technology, the sensitivity floor can reach GUT-scale dark matter candidates. We discuss the scientific challenge of building such a device and the potential implications of dark matter models in this mass range.   

The XENONnT Dark Matter Search Experiment

XENON1T, the largest and most sensitive dark matter direct detection experiment, has set the most stringent upper limit on the spin-independent WIMP-nucleon cross section, with a minimum of 4.1 × 10^-47 cm² for a 30 GeV/c² WIMP. The next step in the XENON program, XENONnT, is now under construction at LNGS. With this upgrade, the XENON collaboration aims to probe spin-independent WIMP-nucleon cross sections as low as 2 × 10^-48 cm² with a 20 tonne-year exposure, using a 6 tonne sensitive target with backgrounds from ²²²Rn and neutrons reduced by an order of magnitude. This talk will give an overview of the XENONnT detector, and discuss improvements to the existing XENON1T infrastructure that will make this next generation of the XENON program possible.   

Model-independent constraints on dark matter annihilation in dwarf spheroidal galaxies

Dwarf spheroidal galaxies are exceptionally clean targets for searches for gamma rays from dark matter annihilation.  Here, I will discuss a general, model-independent formalism for determining bounds on the production of photons from dark matter annihilation in dwarf spheroidal galaxies.  This formalism is applicable to any set of assumptions about dark matter particle physics or astrophysics. As an illustration, I'll present an analysis of gamma-ray data from the Fermi Large Area Telescope, which can be used to derive constraints on a variety of nonstandard dark matter models, several of which have not previously been studied in the context of dwarf galaxy searches.
  

Searching for Dark Matter Decay within the Virgo Cluster with the HAWC Observatory

The Virgo Cluster is a galaxy cluster located roughly 16 Mpc from the Milky Way composed of more than 1300 gravitationally bound elliptical and spiral galaxies. Due to its expected high dark matter (DM) content and close proximity to Milky Way, the Virgo Cluster is one of the best candidates for searches for DM decay. The High Altitude Water Cherenkov (HAWC) Observatory has a wide field of view and observes 1-100 TeV gamma-rays and cosmic rays. It is an ideal instrument for DM searches within extended objects such as the Virgo Cluster. We perform searches for DM decay using 1128 days of HAWC data. No statistically significant signal is detected. Thus, we report lower limits on the DM decay lifetime for 1-100 TeV DM mass range.