Search for dark matter decay of the free neutron from the UCNA experiment:
Abstract
It has been proposed recently that a previously unobserved neutron decay branch to a dark matter particle (χ) could account for the discrepancy in the neutron lifetime observed in experiments that use two different measurement techniques. One of the possible final states discussed includes a single χ along with an e+e- pair. We use data from the UCNA (Ultracold Neutron Asymmetry) experiment to set limits on this decay channel. Coincident electron-like events are detected with ~4π acceptance using a pair of detectors that observe a volume of stored ultracold neutrons. The summed kinetic energy (Ee+e-) from such events is used to set limits, as a function of the χ mass, on the branching fraction for this decay channel. For χ masses consistent with resolving the neutron lifetime discrepancy, we exclude this as the dominant dark matter decay channel at >>5σ level for 100<644keV. If the χ+e+e- final state is not the only one, we set limits on its branching fraction of <10-4 for the above Ee+e- range at >90% confidence level.
- Authors:
- more »
- Publication Date:
- Research Org.:
- Univ. of Kentucky, Lexington, KY (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Org.:
- USDOE
- Contributing Org.:
- UCNA Collaboration
- OSTI Identifier:
- 1439426
- Alternate Identifier(s):
- OSTI ID: 1438065; OSTI ID: 1481650; OSTI ID: 1525826
- Report Number(s):
- LA-UR-18-22249
Journal ID: ISSN 2469-9985; PRVCAN; DE-FG02-97ER41042; TRN: US1900608
- Grant/Contract Number:
- SC0014622; FG02-08ER41557; FG02-97ER41042; 20110043DR; AC05-00OR22725; 89233218CNA000001
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Physical Review C
- Additional Journal Information:
- Journal Volume: 97; Journal Issue: 5; Related Information: @article{PhysRevC.97.035505,title = {New result for the neutron $\ensuremath{\beta}$-asymmetry parameter ${A}_{0}$ from UCNA},author = {Brown, M. A.-P. and Dees, E. B. and Adamek, E. and Allgeier, B. and Blatnik, M. and Bowles, T. J. and Broussard, L. J. and Carr, R. and Clayton, S. and Cude-Woods, C. and Currie, S. and Ding, X. and Filippone, B. W. and Garc\'{\i}a, A. and Geltenbort, P. and Hasan, S. and Hickerson, K. P. and Hoagland, J. and Hong, R. and Hogan, G. E. and Holley, A. T. and Ito, T. M. and Knecht, A. and Liu, C.-Y. and Liu, J. and Makela, M. and Martin, J. W. and Melconian, D. and Mendenhall, M. P. and Moore, S. D. and Morris, C. L. and Nepal, S. and Nouri, N. and Pattie, R. W. and P\'erez Galv\'an, A. and Phillips, D. G. and Picker, R. and Pitt, M. L. and Plaster, B. and Ramsey, J. C. and Rios, R. and Salvat, D. J. and Saunders, A. and Sondheim, W. and Seestrom, S. J. and Sjue, S. and Slutsky, S. and Sun, X. and Swank, C. and Swift, G. and Tatar, E. and Vogelaar, R. B. and VornDick, B. and Wang, Z. and Wexler, J. and Womack, T. and Wrede, C. and Young, A. R. and Zeck, B. A.},collaboration = {UCNA Collaboration},journal = {Phys. Rev. C},volume = {97},issue = {3},pages = {035505},numpages = {9},year = {2018},month = {Mar},publisher = {American Physical Society},doi = {10.1103/PhysRevC.97.035505},url = {https://link.aps.org/doi/10.1103/PhysRevC.97.035505}}; Journal ID: ISSN 2469-9985
- Publisher:
- American Physical Society (APS)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; Neutron decay; dark matter decay; neutron to dark matter decay channel; neutron producing positron-electron pairs
Citation Formats
Sun, X., Adamek, E., Allgeier, B., Blatnik, M., Bowles, T. J., Broussard, L. J., Brown, M. A. -P., Carr, R., Clayton, S., Cude-Woods, C., Currie, S., Dees, E. B., Ding, X., Filippone, B. W., García, A., Geltenbort, P., Hasan, S., Hickerson, K. P., Hoagland, J., Hong, R., Hogan, G. E., Holley, A. T., Ito, T. M., Knecht, A., Liu, C. -Y., Liu, J., Makela, M., Mammei, R., Martin, J. W., Melconian, D., Mendenhall, M. P., Moore, S. D., Morris, C. L., Nepal, S., Nouri, N., Pattie, R. W., Pérez Galván, A., Phillips, D. G., Picker, R., Pitt, M. L., Plaster, B., Ramsey, J. C., Rios, R., Salvat, D. J., Saunders, A., Sondheim, W., Sjue, S., Slutsky, S., Swank, C., Swift, G., Tatar, E., Vogelaar, R. B., VornDick, B., Wang, Z., Wei, W., Wexler, J., Womack, T., Wrede, C., Young, A. R., and Zeck, B. A. Search for dark matter decay of the free neutron from the UCNA experiment: n→χ+e+e–. United States: N. p., 2018.
Web. doi:10.1103/PhysRevC.97.052501.
Sun, X., Adamek, E., Allgeier, B., Blatnik, M., Bowles, T. J., Broussard, L. J., Brown, M. A. -P., Carr, R., Clayton, S., Cude-Woods, C., Currie, S., Dees, E. B., Ding, X., Filippone, B. W., García, A., Geltenbort, P., Hasan, S., Hickerson, K. P., Hoagland, J., Hong, R., Hogan, G. E., Holley, A. T., Ito, T. M., Knecht, A., Liu, C. -Y., Liu, J., Makela, M., Mammei, R., Martin, J. W., Melconian, D., Mendenhall, M. P., Moore, S. D., Morris, C. L., Nepal, S., Nouri, N., Pattie, R. W., Pérez Galván, A., Phillips, D. G., Picker, R., Pitt, M. L., Plaster, B., Ramsey, J. C., Rios, R., Salvat, D. J., Saunders, A., Sondheim, W., Sjue, S., Slutsky, S., Swank, C., Swift, G., Tatar, E., Vogelaar, R. B., VornDick, B., Wang, Z., Wei, W., Wexler, J., Womack, T., Wrede, C., Young, A. R., & Zeck, B. A. Search for dark matter decay of the free neutron from the UCNA experiment: n→χ+e+e–. United States. doi:https://doi.org/10.1103/PhysRevC.97.052501
Sun, X., Adamek, E., Allgeier, B., Blatnik, M., Bowles, T. J., Broussard, L. J., Brown, M. A. -P., Carr, R., Clayton, S., Cude-Woods, C., Currie, S., Dees, E. B., Ding, X., Filippone, B. W., García, A., Geltenbort, P., Hasan, S., Hickerson, K. P., Hoagland, J., Hong, R., Hogan, G. E., Holley, A. T., Ito, T. M., Knecht, A., Liu, C. -Y., Liu, J., Makela, M., Mammei, R., Martin, J. W., Melconian, D., Mendenhall, M. P., Moore, S. D., Morris, C. L., Nepal, S., Nouri, N., Pattie, R. W., Pérez Galván, A., Phillips, D. G., Picker, R., Pitt, M. L., Plaster, B., Ramsey, J. C., Rios, R., Salvat, D. J., Saunders, A., Sondheim, W., Sjue, S., Slutsky, S., Swank, C., Swift, G., Tatar, E., Vogelaar, R. B., VornDick, B., Wang, Z., Wei, W., Wexler, J., Womack, T., Wrede, C., Young, A. R., and Zeck, B. A. Mon .
"Search for dark matter decay of the free neutron from the UCNA experiment: n→χ+e+e–". United States. doi:https://doi.org/10.1103/PhysRevC.97.052501. https://www.osti.gov/servlets/purl/1439426.
@article{osti_1439426,
title = {Search for dark matter decay of the free neutron from the UCNA experiment: n→χ+e+e–},
author = {Sun, X. and Adamek, E. and Allgeier, B. and Blatnik, M. and Bowles, T. J. and Broussard, L. J. and Brown, M. A. -P. and Carr, R. and Clayton, S. and Cude-Woods, C. and Currie, S. and Dees, E. B. and Ding, X. and Filippone, B. W. and García, A. and Geltenbort, P. and Hasan, S. and Hickerson, K. P. and Hoagland, J. and Hong, R. and Hogan, G. E. and Holley, A. T. and Ito, T. M. and Knecht, A. and Liu, C. -Y. and Liu, J. and Makela, M. and Mammei, R. and Martin, J. W. and Melconian, D. and Mendenhall, M. P. and Moore, S. D. and Morris, C. L. and Nepal, S. and Nouri, N. and Pattie, R. W. and Pérez Galván, A. and Phillips, D. G. and Picker, R. and Pitt, M. L. and Plaster, B. and Ramsey, J. C. and Rios, R. and Salvat, D. J. and Saunders, A. and Sondheim, W. and Sjue, S. and Slutsky, S. and Swank, C. and Swift, G. and Tatar, E. and Vogelaar, R. B. and VornDick, B. and Wang, Z. and Wei, W. and Wexler, J. and Womack, T. and Wrede, C. and Young, A. R. and Zeck, B. A.},
abstractNote = {It has been proposed recently that a previously unobserved neutron decay branch to a dark matter particle (χ) could account for the discrepancy in the neutron lifetime observed in experiments that use two different measurement techniques. One of the possible final states discussed includes a single χ along with an e+e- pair. We use data from the UCNA (Ultracold Neutron Asymmetry) experiment to set limits on this decay channel. Coincident electron-like events are detected with ~4π acceptance using a pair of detectors that observe a volume of stored ultracold neutrons. The summed kinetic energy (Ee+e-) from such events is used to set limits, as a function of the χ mass, on the branching fraction for this decay channel. For χ masses consistent with resolving the neutron lifetime discrepancy, we exclude this as the dominant dark matter decay channel at >>5σ level for 100<644keV. If the χ+e+e- final state is not the only one, we set limits on its branching fraction of <10-4 for the above Ee+e- range at >90% confidence level.},
doi = {10.1103/PhysRevC.97.052501},
journal = {Physical Review C},
number = 5,
volume = 97,
place = {United States},
year = {2018},
month = {5}
}
Web of Science
Figures / Tables:

Works referenced in this record:
Measurement of the neutron lifetime using a magneto-gravitational trap and in situ detection
journal, May 2018
- Pattie, R. W.; Callahan, N. B.; Cude-Woods, C.
- Science, Vol. 360, Issue 6389
Colloquium : The neutron lifetime
journal, November 2011
- Wietfeldt, Fred E.; Greene, Geoffrey L.
- Reviews of Modern Physics, Vol. 83, Issue 4
New result for the neutron -asymmetry parameter from UCNA
journal, March 2018
- Brown, M. A. -P.; Dees, E. B.; Adamek, E.
- Physical Review C, Vol. 97, Issue 3
Demonstration of a solid deuterium source of ultra-cold neutrons
journal, July 2004
- Saunders, A.; Anaya, J. M.; Bowles, T. J.
- Physics Letters B, Vol. 593, Issue 1-4
Implications of neutron star properties for the existence of light dark matter
journal, April 2018
- Motta, T. F.; Guichon, P. A. M.; Thomas, A. W.
- Journal of Physics G: Nuclear and Particle Physics, Vol. 45, Issue 5
Multi-wire proportional chamber for ultra-cold neutron detection
journal, February 2009
- Morris, C. L.; Bowles, T. J.; Gonzales, J.
- Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 599, Issue 2-3
Measurement of the neutron -asymmetry parameter with ultracold neutrons
journal, November 2012
- Plaster, B.; Rios, R.; Back, H. O.
- Physical Review C, Vol. 86, Issue 5
The Neutron Enigma
journal, March 2016
- Greene, Geoffrey L.; Geltenbort, Peter
- Scientific American, Vol. 314, Issue 4
Publisher's Note: First direct constraints on Fierz interference in free-neutron decay [Phys. Rev. C 96, 042501(R) (2017)]
journal, November 2017
- Hickerson, K. P.; Sun, X.; Bagdasarova, Y.
- Physical Review C, Vol. 96, Issue 5
A high-field adiabatic fast passage ultracold neutron spin flipper for the UCNA experiment
journal, July 2012
- Holley, A. T.; Broussard, L. J.; Davis, J. L.
- Review of Scientific Instruments, Vol. 83, Issue 7
Precision measurement of the neutron -decay asymmetry
journal, March 2013
- Mendenhall, M. P.; Pattie, R. W.; Bagdasarova, Y.
- Physical Review C, Vol. 87, Issue 3
Geant4—a simulation toolkit
journal, July 2003
- Agostinelli, S.; Allison, J.; Amako, K.
- Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 506, Issue 3
A solenoidal electron spectrometer for a precision measurement of the neutron -asymmetry with ultracold neutrons
journal, October 2008
- Plaster, B.; Carr, R.; Filippone, B. W.
- Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 595, Issue 3
Dark Matter Interpretation of the Neutron Decay Anomaly
journal, May 2018
- Fornal, Bartosz; Grinstein, Benjamín
- Physical Review Letters, Vol. 120, Issue 19
A multiwire proportional chamber for precision studies of neutron decay angular correlations
journal, February 2007
- Ito, T. M.; Carr, R.; Filippone, B. W.
- Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 571, Issue 3
Beta decay measurements with ultracold neutrons: a review of recent measurements and the research program at Los Alamos National Laboratory
journal, October 2014
- Young, A. R.; Clayton, S.; Filippone, B. W.
- Journal of Physics G: Nuclear and Particle Physics, Vol. 41, Issue 11
Open statistical issues in Particle Physics
journal, September 2008
- Lyons, Louis
- The Annals of Applied Statistics, Vol. 2, Issue 3
Sealed drift tube cosmic ray veto counters
journal, May 2011
- Rios, R.; Tatar, E.; Bacon, J. D.
- Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 637, Issue 1
Examining the possibility to observe neutron dark decay in nuclei
journal, April 2018
- Pfützner, M.; Riisager, K.
- Physical Review C, Vol. 97, Issue 4
First direct constraints on Fierz interference in free-neutron decay
journal, October 2017
- Hickerson, K. P.; Sun, X.; Bagdasarova, Y.
- Physical Review C, Vol. 96, Issue 4
Measurements of Ultracold-Neutron Lifetimes in Solid Deuterium
journal, December 2002
- Morris, C. L.; Anaya, J. M.; Bowles, T. J.
- Physical Review Letters, Vol. 89, Issue 27
Performance of the Los Alamos National Laboratory spallation-driven solid-deuterium ultra-cold neutron source
journal, January 2013
- Saunders, A.; Makela, M.; Bagdasarova, Y.
- Review of Scientific Instruments, Vol. 84, Issue 1
Works referencing / citing this record:
Testing Dark Decays of Baryons in Neutron Stars
journal, August 2018
- Baym, Gordon; Beck, D. H.; Geltenbort, Peter
- Physical Review Letters, Vol. 121, Issue 6
Constraints on the Dark Matter Interpretation of the Neutron Decay Anomaly with the PERKEO II Experiment
journal, June 2019
- Klopf, M.; Jericha, E.; Märkisch, B.
- Physical Review Letters, Vol. 122, Issue 22
Figures / Tables found in this record: