Search for dark matter decay of the free neutron from the UCNA experiment: n -> X plus e(+)e(-) Academic Article uri icon


  • 2018 American Physical Society. It has been proposed recently that a previously unobserved neutron decay branch to a dark matter particle () 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 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 4 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 mass, on the branching fraction for this decay channel. For masses consistent with resolving the neutron lifetime discrepancy, we exclude this as the dominant dark matter decay channel at 5 level for 10090% confidence level.

published proceedings


altmetric score

  • 4.75

author list (cited authors)

  • Sun, X., Adamek, E., Allgeier, B., Blatnik, M., Bowles, T. J., Broussard, L. J., ... Zeck, B. A.

citation count

  • 27

complete list of authors

  • Sun, X||Adamek, E||Allgeier, B||Blatnik, M||Bowles, TJ||Broussard, LJ||Brown, MA-P||Carr, R||Clayton, S||Cude-Woods, C||Currie, S||Dees, EB||Ding, X||Filippone, BW||Garcia, A||Geltenbort, P||Hasan, S||Hickerson, KP||Hoagland, J||Hong, R||Hogan, GE||Holley, AT||Ito, TM||Knecht, A||Liu, C-Y||Liu, J||Makela, M||Mammei, R||Martin, JW||Melconian, D||Mendenhall, MP||Moore, SD||Morris, CL||Nepal, S||Nouri, N||Womack, T||Pattie, RW Jr||Galvan, A Perez||Phillips, DGII||Picker, R||Pitt, ML||Plaster, B||Ramsey, JC||Rios, R||Salvat, DJ||Saunders, A||Sondheim, W||Sjue, S||Slutsky, S||Swank, C||Swift, G||Tatar, E||Vogelaar, RB||VornDick, B||Wang, Z||Wei, W||Wexler, J||Womack, T||Wrede, C||Young, AR||Zeck, BA

publication date

  • May 2018