Shooting Neutrinos Through the Earth K2K experiment (and beyond)

by Prof. Shige Matsuno (UHM Physics - High Energy Physics Group)

Thursday Nov 29, 2007, 3:30 PM → 4:30 PM Pacific/Honolulu

Rm 112 (UHM - Watanabe Hall)

The K2K experiment was the first long base line experiment aimed to study neutrino oscillation with a beam of neutrinos generated by an accelerator. It used a 12 GeV proton synchrotron at KEK in Japan as a source to generate neutrinos, and the 250 km distant Super-Kamiokande (SK) detector as a far detector. The flight distance through the earth between KEK and SK permitted these (mostly muon) neutrinos oscillate, and we measured these changes, finding results consistent with the discovery of muon neutrino oscillations in SuperK earlier and employing natural neutrinos from cosmic rays. The experiment finished taking data at the end of 2004 and published their final oscillation paper late last year. It will stand as one of the most important experiments in a history of neutrino oscillation research, and marks the important confirmation of muon neutrino oscillations in an entirely different setting, removing any lingering concerns. Despite the long involvement of UH personal (John Learned, Atsuko Kibayashi, and I), the K2K experiment has not been presented in detail at UH. I'd like to use this opportunity to discuss the principles and results of the experiment. Several experiments that follow on to the K2K effort will also be presented.