SENSITIVITY OF ELECTRON-PROTON COINCIDENCE ASYMMETRIES IN NEUTRON BETA-DECAY TO SCALAR AND TENSOR INTERACTIONS

Author

Subash C. Nepal, University of KentuckyFollow

Date Available

8-4-2020

Year of Publication

2020

Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation

College

Arts and Sciences

Department/School/Program

Physics and Astronomy

First Advisor

Dr. Bradley Plaster

Abstract

We study the combined sensitivity of measurements of electron-proton coincidence asymmetries in polarized neutron beta-decay together with a measurement of the electron energy spectrum in unpolarized neutron beta-decay to beyond Standard Model (BSM) scalar and tensor interactions, via the appearance of such BSM physics in the Fierz interference terms b and b_v. Whereas measurements of the electron energy spectrum directly probe b, both the proton and neutrino asymmetries for which experimental results exist are not sensitive to b_v, but effectively to b - b_v. This results in reduced sensitivity to BSM scalar and tensor physics as the dependencies of b_v and b on scalar and tensor physics are similar. As a remedy, we demonstrate that ratios of certain asymmetries are sensitive only to b_v, thus providing a new paradigm for directly accessing b_v. We find that with 1X10⁹ events, a combined fit to our asymmetry ratios and the spectrum yields sensitivity to b and b_v at the level of ~ 2 x 10^-3.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2020.475

Funding Information

This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Award Number DE-SC0014622, 2017-2020.

Recommended Citation

Nepal, Subash C., "SENSITIVITY OF ELECTRON-PROTON COINCIDENCE ASYMMETRIES IN NEUTRON BETA-DECAY TO SCALAR AND TENSOR INTERACTIONS" (2020). Theses and Dissertations--Physics and Astronomy. 77.
https://uknowledge.uky.edu/physastron_etds/77