Nuclear, Particle, Astroparticle and Cosmology (NUPAC) Seminars
Another way to look at the Dark Matter
Presented by Dr. Jerry Va'vra (SLAC)
At present there is an effort to reconcile the results of the DAMA experiment with other Dark Matter searching experiments. If DAMA and CoGeNT experiment modulation signal is caused by the Dark Matter, it cannot be due to a moderately heavy WIMP recoiling off the Na or I nuclei, as it would be in a conflict with LXe experiments such as LUX and Xenon-100. The presence of a signal in DAMA and CoGeNT, and lack of any signal in all LXe experiments so far, can be explained by a very light WIMP (1 - few GeV/c^2) scattering off the hydrogen nuclei. Hydrogen is a contamination in the NaI(Tl) or Ge crystals. There is no hydrogen in LXe. Any signal measured in LXe will directly contradict this proposal. Since the H-contamination in NaI(Tl) detectors is at ppm level, the WIMP-proton cross-section has to be large.
If the WIMP-proton cross-section is large, the Dark Matter (DM) search could be expanded into a domain of detectors sensitive to molecular excitations. In this talk we investigate in detail di-atomic OH molecules, and water molecules. Presently, we do not have suitable low cost IR detectors to observe single photons, however some OH-molecular excitations extend to visible and UV wavelengths, and can be measured by Bialkali photocathodes. An example of a detector where such search is possible is the Ice Cube experiment and we will discuss status of the search there. In this talk we also touch other possibilities to explain the Dark Matter, namely a molecular hydrogen and so called "small hydrogen atoms".
2:00 pm, Tuesday, November 4, 2014
PAIS-2540, PAIS
Individuals with disabilities who need an auxiliary aid or service to attend or participate in P&A events should contact the Physics Department (phone: 505-277-2616, email: physics@unm.edu) well in advance to ensure your needs are accomodated. Event handouts can be provided in alternative accessible formats upon request. Please contact the Physics front office if you need written information in an alternative format.
A schedule of talks within the Department of Physics and Astronomy is available on the P&A web site at http://physics.unm.edu/pandaweb/events/index.php