NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PUBLICATIONS

A New Limit on Time-Reversal Violation in Beta Decay

Published

Author(s)

Hans P. Mumm, T E. Chupp, K P. Coulter, R L. Cooper, S J. Freedman, B. K. Fujikawa, A. Garcia, Gordon L. Jones, Jeffrey S. Nico, Alan K. Thompson, C A. Trull, J. F. Wilkerson, F. E. Wiefeldt

Abstract

We report the results of an improved determination of the triple correlation DP • (p_e × p_v) that can be used to limit possible time-reversal invariance in the beta decay of polarized neutrons and constrain extensions to the Standard Model. Our result is D = (-0.96 ± 1.89(stat) ± 1.01(sys)) × 10e-4. The corresponding phase between g_A and g_V is 180.013 ± 0.028 degrees (68% confidence level). This result represents the most sensitive measurement of D in nuclear beta decay.
Citation
Physical Review Letters
Volume
107
Pub Type
Journals

Keywords

baryon asymmetry, neutron decay, symmetries, time-reversal
Neutron research

Citation

Mumm, H. , Chupp, T. , Coulter, K. , Cooper, R. , Freedman, S. , Fujikawa, B. , Garcia, A. , Jones, G. , Nico, J. , Thompson, A. , Trull, C. , Wilkerson, J. and Wiefeldt, F. (2012), A New Limit on Time-Reversal Violation in Beta Decay, Physical Review Letters (Accessed October 7, 2025)

Issues

If you have any questions about this publication or are having problems accessing it, please contact [email protected].

Created September 2, 2012, Updated February 19, 2017
Was this page helpful?