This award supports the University of California-Berkeley group to continue their participation in the newly completed IceCube Neutrino Observatory at the South Pole. The Berkeley group plays a leading role in calibrations, monitoring, simulations, operations, management, and other service tasks in addition to analyzing data. Over the period of this award the group will engage in a range of physics and astrophysics research. Using the newly available and powerful background veto capabilities of the cubic kilometer detector the group will measure atmospheric neutrino-induced cascades and search for a diffuse extraterrestrial flux of high-energy electron neutrinos. The goal is the first definitive detection of electromagnetic and hadronic particle showers initiated by interactions of high-energy neutrinos in a medium. They will search for violation of Lorentz-invariance and superluminal neutrinos using high-energy neutrinos detected by IceCube to improve the current limit or find a violation using time-of-flight measurements with respect to gamma-ray bursts and core-collapse supernovae. Finally, they will use data from DeepCore, the low energy extension of IceCube, for high-statistics measurements probing the dark matter and neutrino oscillations sectors. These measurements will depend on precise knowledge of geometrical and optical detector and ice properties. The Berkeley group will extend their measurements of the optical properties of the deep ice with measurements of the scattering function and the properties of the columns of refrozen ice surrounding the optical sensors.
Broader Impacts: Members of the group will visit and give talks to students at nearby colleges with predominantly minority enrollments, to local groups of amateur astronomers, and to the general public. The PI will give talks to business leaders in the Bay Area and give talks and advise scientists in developing countries. Members of the group will communicate with reporters writing about science in the popular press and coordinate outreach activities involving the Teachers Experiencing Antarctica program and the Upward Bound program. The group is also involved in spin-off projects, through its inventions of novel instruments such as the optical dust logger and the biospectral logger. These projects advance our understanding of climate change and microbial life under extreme conditions close to those on Mars. The group will continue communications with glaciologists who use results from the Berkeley group's ice measurements to get a more complete understanding of glacial ice, and the movement and fate of the Antarctic ice sheet.
