Astroparticle Physics with the IceCube Neutrino Observatory

Michigan State University, East Lansing MI

Investigators

Abstract

Embedded deep in the ice cap at the South Pole, the IceCube Neutrino Observatory (ICNO) is the world's largest and most sensitive high energy neutrino telescope. It is a 1 billion-ton detector using the Antarctic ice as a detection medium for high energy atmospheric and astrophysical neutrinos. Most of the neutrinos observed by IceCube exhibit energies in the range expected for atmospheric neutrinos originating from decays of particles produced in extensive air showers by cosmic rays coming from nearby sectors of the Milky Way Galaxy. These may be used to measure the fundamental properties of neutrinos. At higher energies, astrophysical neutrinos are key probes of the high-energy universe. Because of their unique properties, neutrinos escape even dense regions, are not deflected by galactic or extra-galactic magnetic fields and traverse the photon-filled universe unhindered. Thus, neutrinos provide direct information about the dynamics and interiors of the powerful cosmic objects that may be the origins of high energy cosmic rays: supernovae, black holes, pulsars, active galactic nuclei and other extreme extragalactic phenomena. Development of a diverse STEM workforce is an important goal, and women and members of under-represented minority groups have made up more than half of the graduate and undergraduate students in the research group. Hands-on research opportunities are provided to several undergraduates working on key IceCube research topics. The group engages the public with this research at a variety of levels and through a variety of media. This award also supports an IceCube MasterClass workshop for local high school students, giving them experience with analysis of real IceCube data, using the highly successful program developed for IceCube at the University of Wisconsin and delivered at collaborating institutions around the world. The IceCube Observatory was designed primarily to observe very high energy neutrinos from galactic and extragalactic sources. An inner array known as DeepCore, located in the center of IceCube, also permits observation of neutrinos with energies at which flavor oscillations are visible. This award supports oscillation measurements with precision comparable to the current world-leading results from the MINOS, T2K, and NOvA experiments, but at much higher energies - providing a complementary view of neutrino oscillations with broad sensitivity to new physics. In addition, the relatively high energy range of DeepCore allows the world's highest precision measurement of tau neutrino appearance: a direct, model-independent test of the standard theories of neutrino oscillations and neutrino interactions with matter. IceCube data is also used to search for dark matter in the Sun and our Galaxy, with world-leading sensitivity to some models of dark matter.