Modeling beta decay spectra to analyze the sensitivity of a neutrino mass experiment

The Project 8 experiment aims to measure the electron neutrino mass by obtaining and analyzing [beta] spectra from tritium decay. Using an inferential model of the experiment's anticipated data, I evaluate its projected sensitivity to certain parameters of interest. I focus on the precision and accuracy with which Project 8 can expect to resolve the [beta]-decay spectrum's endpoint in an upcoming stage of the experiment. I also present an initial prediction of Project 8's eventual expected sensitivity to the electron neutrino mass. This analysis involved generating and analyzing [beta]-decay spectral data using a model implemented in Stan, a platform for Bayesian statistical inference. The sensitivity analysis was designed to account for the anticipated distribution of results (mass and endpoint measurements) produced by the potential variation in a number of physical and experimental parameters. In addition, the method used here allows for a calibration of the consequences of inferences and decisions made in reaching those results. I find that, using one year of Project 8 Phase II data, the T2 endpoint can be resolved within a 13.7 eV window (90% C.I.) with 62% coverage (or accuracy), corresponding to a 4.1 eV posterior standard deviation. Preliminarily, using one year of Phase IV data, the electron neutrino mass can be resolved within a 0.051 eV window (90% C.I.) with 56% coverage. I also outline a way that model-based sensitivity procedures and calibration of inference can be extended to the neutrino mass hierarchy problem.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Physics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2018

Author dc:creator

• Weiss, Talia E

Advisor dc:contributor.advisor

• Joseph A. Formaggio.

• Physics.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/120207

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/120207