Session B5: Dark Matter

New approaches to dark matter and neutrino detection

Two new initiatives in astroparticle and neutrino physics will be discussed: COUPP employs ultra-stable heavy liquid bubble chambers to search for WIMP dark matter. First results leading to improved limits on spin-dependent WIMP couplings will be presented, together with the most recent progress and prospects. COGENT aims at the detection of very faint ($\sim$100 eV) signals in detectors massive enough ($\sim$1 kg) to allow searches for rare processes, using recently developed p-type point contact (ppc) Germanium detectors. The broad range of applications (coherent neutrino scattering, light WIMP searches, double-beta decay) available to these new semiconductor devices will be described. First results from their underground operation will be presented, as well as the status of an ongoing reactor deployment.   

The race to detect WIMP dark matter with liquid noble-based detectors

The direct search for WIMP dark matter is on the verge of a major increase in sensitivity, in particular due to the advent of detectors based on liquified noble elements. The best dark matter limits are now from XENON10, a two-phase xenon detector with 5 kg fiducial mass, and a set of larger, next generation experiments based on Ar and Xe are planed or underway. This includes the 300 kg LUX experiment, of which I am a member, and which will operate in the historic Davis cavern in the new SUSEL lab in South Dakota. These technologies and the proposed DUSEL underground laboratory offer an unprecedented opportunity for dark matter searches with sensitive masses up to at least 10 tons. This would provide a nearly- complete test of dark matter at the weak scale.   

Indirect Detection of Dark Matter in a New Experimental Era

The discovery of the nature of dark matter has been a major goal of Particle Astrophysics over the past two decades. In order to establish the existence of particle dark matter one needs (in no particular order) to detect dark matter as particles in the galaxy and the universe, and detect the identical particles in controlled environments at particle accelerators. Indirect detection of dark matter is the method used to detect dark matter particles via the decay products of their annihilation or decay in situ in the galaxy and the universe. The decay products most commonly used as dark matter messengers in current searches are photons, electrons, positrons, protons, antiprotons, and neutrinos. Indirect detection methods use both information about the particle physics model needed to calculate annihilation or decay rates, and the source structure of the dark matter under consideration, e.g., the density distribution of dark matter halo of the galaxy. In addition, depending on which particle messenger is used, astrophysical backgrounds can be more or less a source of confusion to a potential signal and need to be well understood via subsidiary measurement before reliable limits can be reported or a discovery claimed. A new experimental era promising much better limits or (hopefully) a discovery will soon begin. New indirect detections experiments involving space based satellites (the Large Area Space Telescope, GLAST is one of my favorites), ground based gamma ray telescopes, and neutrino telescopes have recently started operation or are coming on line this year. In addition, improved underground based direct detection experiments and of course the LHC are also beginning operation latter this year. In my talk I will review the current status of indirect detection experiments, and speculate on what the dramatic improvement of experimental capability expected this year might bring.