Measurement of the free neutron lifetime in a magneto-gravitational trap with <i>in situ</i> detection
Here we publish three years of data from the UCN\ensuremath{\tau} experiment performed at the Los Alamos Ultracold Neutron Facility at the Los Alamos Neutron Science Center. These data are in addition to our previously published data. Our goals in this paper are to better understand and quantify systematic uncertainties and to improve the lifetime statistical precision. We previously reported a value from our 2017--2018 data for the neutron lifetime of $877.75\ifmmode\pm\else\textpm\fi{}0.28$ (statistical) +0.22--0.16 (systematic) s. We have collected an additional three years of data reported here for the first time. When all the data from UCN\ensuremath{\tau} are averaged for 2017, 2018, 2020, 2021, and 2022, we report an updated value for the lifetime of $877.83\ifmmode\pm\else\textpm\fi{}0.22$ (statistical)+0.20--0.17 (systematic) s. We utilized improved monitor detectors, reduced our correction due to UCN upscattering on residual gas, and employed four different UCN detector geometries both to reduce the correction required for rate dependence and to explore potential contributions due to phase space evolution.
Authors
- K.P. Hickerson (ORCID: https://orcid.org/0000-0001-7647-119X)
- P. Geltenbort (ORCID: https://orcid.org/0000-0001-9045-3801)
- R. W. Pattie (ORCID: https://orcid.org/0000-0003-4368-4417)
- S. Lin (ORCID: https://orcid.org/0000-0003-1934-1588)
- Francisco M. González (ORCID: https://orcid.org/0000-0002-5954-4155)
- Nathan Callahan (ORCID: https://orcid.org/0000-0002-8589-3260)
- Zhehui Wang (ORCID: https://orcid.org/0000-0001-7826-4063)
- M. Makela (ORCID: https://orcid.org/0000-0003-0592-3683)
- R. Musedinovic (ORCID: https://orcid.org/0000-0003-1136-3918)
- W. Fox (ORCID: https://orcid.org/0000-0001-6289-858X)
- C. Cude-Woods (ORCID: https://orcid.org/0000-0003-0557-8189)
- M. Blatnik (ORCID: https://orcid.org/0000-0003-3496-0010)
- J. Ramsey (ORCID: https://orcid.org/0000-0001-6491-3288)
- C. O’Shaughnessy (ORCID: https://orcid.org/0000-0002-0428-7374)
- L. Blokland
- A. T. Holley
- B. W. Filippone (ORCID: https://orcid.org/0000-0002-2618-2688)
- Z. Tang (ORCID: https://orcid.org/0000-0002-7328-3086)
- D. J. Salvat (ORCID: https://orcid.org/0000-0002-0556-5436)
- E. I. Sharapov (ORCID: https://orcid.org/0000-0002-5287-3837)
- S. J. Seestrom (ORCID: https://orcid.org/0009-0004-7282-9202)
- Steven Clayton (ORCID: https://orcid.org/0000-0002-1401-2761)
- J. H. Choi (ORCID: https://orcid.org/0000-0002-3768-1634)
- T. M. Ito (ORCID: https://orcid.org/0000-0003-3494-6796)
- A. R. Young (ORCID: https://orcid.org/0000-0002-7326-7414)
- C. L. Morris (ORCID: https://orcid.org/0000-0003-2141-0255)
- A. Komives (ORCID: https://orcid.org/0000-0002-9377-6064)
- L. Hayen (ORCID: https://orcid.org/0000-0002-9471-0964)
- J. Vanderwerp
- M. S. Singh (ORCID: https://orcid.org/0000-0002-2385-0492)
- C.-Y. Liu
- Peter Walstrom
- F. Uhrich (ORCID: https://orcid.org/0000-0002-7711-0748)
- E. M. Fries (ORCID: https://orcid.org/0000-0002-3788-8096)
- A. Saunders
Institutions
- East Tennessee State University (US)
- DePauw University (US)
- California Institute of Technology (US)
- Argonne National Laboratory (US)
- Oak Ridge National Laboratory (US)
- Los Alamos National Laboratory (US)
- North Carolina State University (US)
- University of Illinois System (US)
- Joint Institute for Nuclear Research (RU)
- Triangle Universities Nuclear Laboratory (US)
- Institut Laue-Langevin (FR)
- Indiana University (US)
- Tennessee Technological University (US)
Publication Details
- Journal
- Physical review. C
- Published
- 2025-04-07
- DOI
- https://doi.org/10.1103/physrevc.111.045501
- Citations
- 6
- Primary Topic
- Atomic and Subatomic Physics Research
- Type
- article
- Field-Weighted Citation Impact
- 7.48
Funders
- National Science Foundation
- U.S. Department of Energy
- Office of Science
- Nuclear Physics