Direct observation of dark matter will have profound implications in astrophysics and particle physics. By directly observing dark matter particles in our detectors, we will be able to determine the nature of the particles that make up to 83% of the mass of the universe. These studies will offer a unique window on physics beyond the Standard Model, and are complementary to searches for New Physics at the Large Hadron Collider. Direction-sensitive Weakly Interacting Massive Particle (WIMP) detectors will provide the most convincing evidence for direct observation of dark matter due to their excellent background rejection capabilities. The correlation between the energy and length of the recoil track allows for a powerful rejection of backgrounds due to photons, electrons, and alpha particles. In addition, the correlation between the measured direction of the nuclear recoil and the expected direction of the dark matter wind allows for an efficient rejection of more insidious backgrounds, such as neutrons and solar neutrinos. Finally, directionality can discriminate between various dark matter halo models in our Galaxy, making directional detectors unique observatories for underground WIMP astronomy.
This award will provide funding to construct a detector that measures the direction of the WIMP particles as well as their recoil energy, to provide an unambiguous observation of dark matter, even in the presence of backgrounds. The detector proposed is DMTPCino, a 1 cubic meter, low-pressure time projection chamber (TPC) with optical readout.
The technology can be used for several applications outside particle physics, such as neutron detection for homeland security and defense applications, to scan for potentially hazardous materials through the emission of fission-spectrum neutrons. Applications of the DMTPC principle as an imaging device for medical and biological applications are also under study. The DMTPCino experiment is ideal for educating and training the next generation of particle physicists.
