Precision Measurement of Neutrino Oscillation Parameters and Investigation of Nuclear Georeactor Hypothesis with KamLAND

Author: Zhang, Chao

Year: 2011

Degree: Dissertation (Ph.D.)

Advisor: McKeown, Robert D.

Committee Members: McKeown, Robert D.; Filippone, Bradley W.; Golwala, Sunil; Vogel, Petr

Option: Physics

DOI: 10.7907/ME5M-F406

Abstract

A combined analysis of examining the neutrino oscillation parameters and investigation of nuclear georeactor hypothesis with the KamLAND experiement is presented. With a total exposure of 2.75 kton-years, 930 anti-electron-neutrino candidate events above 3.4 MeV neutrino energy threshold were detected, with estimated 109±13 events from backgrounds. Assuming CPT invariance by combining with solar neutrino results, the best-fit value of georeactor fission power is 4.9+3.8-4.8 TW. The 90% upper limit on the georeactor power is determined to be 11.2 TW. This result has put a significant constraint on the contribution of a possible georeactor to the total heat from the Earth. The best-fit values of the neutrino oscillation parameters, including the georeactor power as a free parameter, is consistent with KamLAND's previously published results with null-georeactor assumption.

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