Dark Matter Implications of the DAMA/LIBRA-phase 2 results

Prof. Christopher Kelso (host Dev), University of North Florida
May 3, 2018 at 3:00 pm
241 Compton
Event Description 

The nature of dark matter is one of the most compelling mysteries in modern physics. A wealth of evidence for the existence of dark matter has been obtained, from observations of the rotation of spiral galaxies, the cosmic microwave background, and the collisions of galaxy clusters, as well as from simulations of the formation of the largest structures in the cosmos. For over 20 years, the DAMA/LIBRA collaboration has observed an annual modulation signal in their detectors that is compatible with a dark matter interpretation. Recently, the collaboration released updated results from their search for the annual modulation signal. Besides approximately doubling the exposure of the DAMA/LIBRA data set, the upgraded photomultiplier tubes of the experiment lower the recoil energy threshold to 1 keV electron equivalent from the previous threshold of 2 keV electron equivalent.

Due to a conspiracy of multiple effects, the new data at low recoil energies is very powerful for testing the Dark Matter hypothesis. We find that canonical (isospin conserving) Spin Independent (SI) WIMP-nucleon interactions are now strongly disfavored. Allowing for Isospin Violating interactions, we find new best fit regions for spin independent scattering with suppressed effective couplings to iodine for Dark Matter masses of ~10 GeV and ~45 GeV.

Coffee: 2:45 pm, 241 Compton