Improved Neutron Lifetime Measurement with UCNτ
- Creators
- Gonzalez, F. M.
- Fries, E. M.
- Cude-Woods, C.
- Bailey, T.
- Blatnik, M.
- Broussard, L. J.
- Callahan, N. B.
- Choi, J. H.
- Clayton, S. M.
- Currie, S. A.
- Dawid, M.
- Dees, E. B.
- Filippone, B. W.
- Fox, W.
- Geltenbort, P.
- George, E.
- Hayen, L.
- Hickerson, K. P.
- Hoffbauer, M. A.
- Hoffman, K.
- Holley, A. T.
- Ito, T. M.
- Komives, A.
- Liu, C.-Y.
- Makela, M.
- Morris, C. L.
- Musedinovic, R.
- O'Shaughnessy, C.
- Pattie, R. W.
- Ramsey, J.
- Salvat, D. J.
- Saunders, A.
- Sharapov, E. I.
- Slutsky, S.
- Su, V.
- Sun, X.
- Swank, C.
- Tang, Z.
- Uhrich, W.
- Vanderwerp, J.
- Walstrom, P.
- Wang, Z.
- Wei, W.
- Young, A. R.
- UCNτ Collaboration
Abstract
We report an improved measurement of the free neutron lifetime τ_n using the UCNτ apparatus at the Los Alamos Neutron Science Center. We count a total of approximately 38 × 10⁶ surviving ultracold neutrons (UCNs) after storing in UCNτ's magnetogravitational trap over two data acquisition campaigns in 2017 and 2018. We extract τ_n from three blinded, independent analyses by both pairing long and short storage time runs to find a set of replicate τ_n measurements and by performing a global likelihood fit to all data while self-consistently incorporating the β-decay lifetime. Both techniques achieve consistent results and find a value τ_n = 877.75 ± 0.28_(stat) + 0.22/−0.16_(syst) s. With this sensitivity, neutron lifetime experiments now directly address the impact of recent refinements in our understanding of the standard model for neutron decay.
Additional Information
© 2021 American Physical Society. (Received 18 June 2021; accepted 20 July 2021; published 13 October 2021) This work is supported by the LANL LDRD program; the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Awards No. DE-FG02-ER41042, No. DE-AC52-06NA25396, No. DE-AC05-00OR2272, and No. 89233218CNA000001 under proposal LANLEEDM; NSF Grants No. 1614545, No. 1914133, No. 1506459, No. 1553861, No. 1812340, No. 1714461, and No. 1913789; and NIST precision measurements grant.Attached Files
Published - PhysRevLett.127.162501.pdf
Accepted Version - 2106.10375.pdf
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Additional details
- Alternative title
- An improved neutron lifetime measurement with UCNτ
- Eprint ID
- 111450
- Resolver ID
- CaltechAUTHORS:20211014-212143728
- Los Alamos National Laboratory
- Department of Energy (DOE)
- DE-FG02-ER41042
- Department of Energy (DOE)
- DE-AC52-06NA25396
- Department of Energy (DOE)
- DE-AC05-00OR2272
- Department of Energy (DOE)
- 89233218CNA000001
- NSF
- PHY-1614545
- NSF
- PHY-1914133
- NSF
- PHY-1506459
- NSF
- PHY-1553861
- NSF
- PHY-1812340
- NSF
- PHY-1714461
- NSF
- PHY-1913789
- National Institute of Standards and Technology (NIST)
- Created
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2021-10-18Created from EPrint's datestamp field
- Updated
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2023-03-16Created from EPrint's last_modified field