Measurement of neutrino mixing angle Θ13 in the Daya Bay Reactor Neutrino Experiment

Ngai, Wah Kai

Permalink

https://hdl.handle.net/2142/34258 Copy

Description

Title

Measurement of neutrino mixing angle Θ13 in the Daya Bay Reactor Neutrino Experiment

Author(s)

Ngai, Wah Kai

Issue Date

2012-09-18T21:08:17Z

Director of Research (if dissertation) or Advisor (if thesis)

Peng, Jen-Chieh

Doctoral Committee Chair(s)

Thaler, Jonathan J.

Committee Member(s)

• Willenbrock, Scott S.
• Kwiat, Paul G.
• Peng, Jen-Chieh

Department of Study

Physics

Discipline

Physics

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• neutrino
• Mixing
• angle
• theta13
• daya bay
• reactor

Abstract

Neutrino oscillations have been observed in experiments measuring solar, atmospheric, accelerator and reactor neutrinos. The phenomenon can be described by three mixing angles and three phases. The values of two mixing angles $\theta_{12}$ and $\theta_{23}$ have been pinned down while the value of $\theta_{13}$ was poorly known. The Daya Bay Reactor Antineutrino Experiment was designed to measure $\sin^{2}2\theta_{13}$ with a sensitivity of 0.01 or better by detecting antineutrinos from nuclear reactors with multiple identically designed detectors at different baselines. Antineutrinos were identified by inverse beta decay $\bar{\nu}_{e} + p \rightarrow e^{+} + n$ in 20~tons of Gadolinium-doped liquid scintillator which served as both target and detector. A search for $\bar{\nu}_{e}$ deficits, a process which would manifest a nonzero value of the $\theta_{13}$ mixing angle, was performed. Between December 2011 and Feb 2012, 55 days of data were collected. During this time, 80376 and 10416 electron antineutrino candidates were detected with 1545 and 515 expected background events at the near sites and the far site respectively. A rate-only analysis supports neutrino flavor oscillation with $\sin^{2}2\theta_{13} = 0.0936\pm0.0172$ in a 2-neutrino mixing framework.

Graduation Semester

2012-08

Permalink

http://hdl.handle.net/2142/34258

Copyright and License Information

Copyright 2012 Wah Kai Ngai

Owning Collections