Space-based measurement of the neutron lifetime using data from the neutron spectrometer on NASA's MESSENGER mission

Wilson, Jack T.; Lawrence, David J.; Peplowski, Patrick N.; Eke, Vincent R.; Kegerreis, Jacob A.

Abstract

We establish the feasibility of measuring the neutron lifetime via an alternative, space-based class of methods, which use neutrons generated by galactic cosmic ray spallation of planets surfaces and atmospheres. Free neutrons decay via the weak interaction with a mean lifetime of around 880 s. This lifetime constrains the unitarity of the CKM matrix and is a key parameter for studies of Big-Bang nucleosynthesis. However, current laboratory measurements, using two independent approaches, differ by over 4σ. Using data acquired in 2007 and 2008 during flybys of Venus and Mercury by NASA’s MESSENGER spacecraft, which was not designed to make this measurement, we estimate the neutron lifetime to be 780 ± 60stat ± 70syst s, thereby demonstrating the viability of this new approach.

Citation

Wilson, J. T., Lawrence, D. J., Peplowski, P. N., Eke, V. R., & Kegerreis, J. A. (2020). Space-based measurement of the neutron lifetime using data from the neutron spectrometer on NASA's MESSENGER mission. Physical Review Research, 2(2), Article 023316. https://doi.org/10.1103/physrevresearch.2.023316

• Journal Article Type: Article
• Acceptance Date: May 6, 2020
• Online Publication Date: Jun 11, 2020
• Publication Date: 2020-06
• Deposit Date: Jun 12, 2020
• Publicly Available Date: Jun 12, 2020
• Journal: Physical Review Research
• Electronic ISSN: 2643-1564
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 2
• Issue: 2
• Article Number: 023316
• DOI: https://doi.org/10.1103/physrevresearch.2.023316
• Public URL: https://durham-repository.worktribe.com/output/1262773