Daniel McKinsey
Yale University
Graduate Student
Recruiting Weekend
Note Different Date and
Time
Tea at 4:00 pm
Friday, March
27, 2009
4:30 pm in SPL 57
The Search for the Fundamental Nature of Dark Matter
Abstract: Astrophysical evidence on a variety of distance scales clearly shows that we cannot account for a large fraction of the mass of the universe. This matter is “dark”, not emitting or absorbing any electromagnetic radiation. A compelling explanation for this missing mass is the existence of Weakly Interacting Massive Particles (WIMPs).
These particles are well motivated by particle physics theories beyond the Standard Model, and the discovery of WIMPs would have enormous impact on both astrophysics and particle physics. WIMPs, if they exist, would occasionally interact with normal matter. With a mass in the range of 1 to 1000 times the mass of the proton, and moving at speeds relative to the Earth of about 220 km/s (the velocity of the Sun around the MilkyWay), WIMPs would only deposit a small amount of energy when scattering with nuclei.
Detectors that are low in radioactivity and sensitive to small energy depositions can search for the rare nuclear recoil events predicted by WIMP models. In recent years, several new efforts on direct dark matter detection have begun in which the detection material is a noble liquid. Advantages include: large nuclear recoil signals in both scintillation and ionization channels, good scalability to large target masses, effective discrimination against gamma ray backgrounds, easy purification, and reasonable cost.
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