This three year award will allow the University of Minnesota, Duluth particle physics group to continue studies within the RUI program related to neutrino physics and cosmic ray physics. The intellectual merit of such studies is well established. The group consists of two faculty and M.S. and undergraduate students. It will continue to contribute to operational support for the Fermilab MINOS far detector located in the Soudan Underground Laboratory and in the preparation of the NOvA far detector - all located in northern Minnesota. Physics analyses in support of the neutrino oscillations and neutrino interactions programs with MINOS as well as the MINERvA detector at Fermilab will continue. In addition, contributions to the field of particle astrophysics are supported via studies of the cosmic ray interactions in the neutrino detectors, the use of the MINOS far detector in the detection of astrophysical neutrino sources, and the development of software to allow for similar studies with NOvA.. The broader impacts are impressive. This program provides support for the practical research education of both M.S. and undergraduate physics students. The close proximity of the campus to the detector sites provides the students with a unique opportunity to participate in research at a lab on a regular basis. In addition, the PIs lead a program in which high school teachers and undergraduate interns become involved with the research at the Soudan Lab and give tours to the public and school groups. This and the annual open house serve to connect the activities at the lab to the general public, especially the northern Minnesota communities surrounding the Soudan Lab and the NOvA far detector site.
Supported by this NSF grant, our understanding of neutrinos took huge steps. The long running MINOS experiment produced its final oscillation results, measurements of three of the neutrino mixing or mass parameters obtained from muon neutrino and anti-neutrino disappearance and electron neutrino appearance. A UMD Co-PI also led the improved MINOS time of flight measurement, which confirms with new precision that neutrinos' speed is consistent with at or below the speed of light. After years of construction, the MINERvA neutrino interaction experiment published its first results, in which we described the quasi-elastic process and pointed out a discrepancy in the amount of energy going to very low energy particles near the neutrino interaction point. In addition to direct work in support of this analysis, a co-PI led (and several UMD students contributed to) the test beam effort which produced a vital calibration constraint just in time for these MINERvA results. This NSF grant also supported work on particle astrophysics topics within MINOS. This grant supported development of new experiments as well. NOvA is coming online now, with UMD being responsible for the software trigger system and leading the non-accelerator topics analysis group, with a particular interest in ensuring NOvA could record the flurry of neutrinos from a potential galactic supernova. A student led the study of including events whose muons exit the NOvA detector and how that sample will improve the overall sensitivity of the NOvA measurements. Finally, we started initial work toward the LBNE experiment: a fast Monte Carlo simulation, with particular focus on improving the sensitivity studies by incorporating more realistic resolution and systematic uncertainties.
