Journal of High Energy Physics

, 2019:53 | Cite as

Annihilation signatures of neutron dark decay models in neutron oscillation and proton decay searches

  • Wai-Yee Keung
  • Danny Marfatia
  • Po-Yan TsengEmail author
Open Access
Regular Article - Theoretical Physics


We point out that two models that reconcile the neutron lifetime anomaly via dark decays of the neutron, also predict dark matter-neutron (\( \overline{\chi} \)n) annihilation that may be observable in neutron-antineutron oscillation and proton decay searches at Super-Kamiokande, Hyper-Kamiokande and DUNE. We study signatures of \( \overline{\chi} \)nγπ0 (or multi-π0) and \( \overline{\chi} \)nϕγπ0 (or ϕ+multi-π0), where ϕ is an almost massless boson in one of the two models.


Beyond Standard Model 


Open Access

This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited


  1. [1]
    A. Pichlmaier, V. Varlamov, K. Schreckenbach and P. Geltenbort, Neutron lifetime measurement with the UCN trap-in-trap MAMBO II, Phys. Lett. B 693 (2010) 221 [INSPIRE].
  2. [2]
    A. Steyerl et al., Quasielastic scattering in the interaction of ultracold neutrons with a liquid wall and application in a reanalysis of the Mambo I neutron-lifetime experiment, Phys. Rev. C 85 (2012) 065503 [INSPIRE].
  3. [3]
    S. Arzumanov et al., A measurement of the neutron lifetime using the method of storage of ultracold neutrons and detection of inelastically up-scattered neutrons, Phys. Lett. B 745 (2015) 79 [INSPIRE].
  4. [4]
    J. Byrne and P.G. Dawber, A revised value for the neutron lifetime measured using a penning trap, Europhys. Lett. 33 (1996) 187 [INSPIRE].ADSCrossRefGoogle Scholar
  5. [5]
    A.T. Yue et al., Improved determination of the neutron lifetime, Phys. Rev. Lett. 111 (2013) 222501.Google Scholar
  6. [6]
    Particle Data Group, Review of particle physics, Chin. Phys. C 40 (2016) 100001.Google Scholar
  7. [7]
    B. Fornal and B. Grinstein, Dark matter interpretation of the neutron decay anomaly, Phys. Rev. Lett. 120 (2018) 191801 [arXiv:1801.01124] [INSPIRE].
  8. [8]
    B. Fornal and B. Grinstein, Neutron lifetime discrepancy as a sign of a dark sector?, arXiv:1810.00862 [INSPIRE].
  9. [9]
    M. Pfützner and K. Riisager, Examining the possibility to observe neutron dark decay in nuclei, Phys. Rev. C 97 (2018) 042501 [arXiv:1803.01334] [INSPIRE].
  10. [10]
    M. Jin and Y. Gao, Nucleon-light dark matter annihilation through baryon number violation, Phys. Rev. D 98 (2018) 075026 [arXiv:1808.10644] [INSPIRE].
  11. [11]
    D. McKeen, A.E. Nelson, S. Reddy and D. Zhou, Neutron stars exclude light dark baryons, Phys. Rev. Lett. 121 (2018) 061802 [arXiv:1802.08244] [INSPIRE].
  12. [12]
    G. Baym, D.H. Beck, P. Geltenbort and J. Shelton, Testing dark decays of baryons in neutron stars, Phys. Rev. Lett. 121 (2018) 061801 [arXiv:1802.08282] [INSPIRE].
  13. [13]
    T.F. Motta, P.A.M. Guichon and A.W. Thomas, Implications of neutron star properties for the existence of light dark matter, J. Phys. G 45 (2018) 05LT01 [arXiv:1802.08427] [INSPIRE].
  14. [14]
    B. Grinstein, C. Kouvaris and N.G. Nielsen, Neutron star stability in light of the neutron decay anomaly, arXiv:1811.06546 [INSPIRE].
  15. [15]
    J.J. de Swart, M.C.M. Rentmeester and R.G.E. Timmermans, The status of the pion-nucleon coupling constant, PiN Newslett. 13 (1997) 96 [nucl-th/9802084] [INSPIRE].
  16. [16]
    Y. Aoki, T. Izubuchi, E. Shintani and A. Soni, Improved lattice computation of proton decay matrix elements, Phys. Rev. D 96 (2017) 014506 [arXiv:1705.01338] [INSPIRE].
  17. [17]
    Super-Kamiokande collaboration, Search for proton decay via pe + π 0 and pμ + π 0 in 0.31 megaton · years exposure of the Super-Kamiokande water Cherenkov detector, Phys. Rev. D 95 (2017) 012004 [arXiv:1610.03597] [INSPIRE].
  18. [18]
    Super-Kamiokande collaboration, The search for n\( \overline{n} \) oscillation in Super-Kamiokande I, Phys. Rev. D 91 (2015) 072006 [arXiv:1109.4227] [INSPIRE].
  19. [19]
    G.S. Mutchler et al., Measurement of the imaginary part of the I = 1 \( \overline{N} \) N S-wave scattering length, Phys. Rev. D 38 (1988) 742 [INSPIRE].
  20. [20]
    OBELIX collaboration, Total and annihilation \( \overline{n} \) p cross-sections from 50 MeV/c to 400 MeV/c, Nucl. Phys. A 655 (1999) 224 [INSPIRE].
  21. [21]
    OBELIX collaboration, np annihilation in flight in two mesons in the momentum range between 50 MeV/c and 400 MeV/c with OBELIX, Nucl. Phys. Proc. Suppl. 56 (1997) 227 [INSPIRE].
  22. [22]
    BROOKHAVEN-HOUSTON-PENNSYLVANIA STATE-RICE collaboration, Measurement of anti-neutron proton total and annihilation cross-sections from 100 MeV/c to 500 MeV/c, Phys. Rev. D 36 (1987) 659 [INSPIRE].
  23. [23]
    A. Belyaev, N.D. Christensen and A. Pukhov, CalcHEP 3.4 for collider physics within and beyond the Standard Model, Comput. Phys. Commun. 184 (2013) 1729 [arXiv:1207.6082] [INSPIRE].
  24. [24]
    M. Astrua et al., Antineutron nucleus annihilation cross-sections below 400 MeV/c, Nucl. Phys. A 697 (2002) 209 [INSPIRE].
  25. [25]
    Hyper-Kamiokande collaboration, Hyper-Kamiokande design report, arXiv:1805.04163 [INSPIRE].
  26. [26]
    DUNE collaboration, Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE), arXiv:1512.06148 [INSPIRE].
  27. [27]
    G.J. Feldman and R.D. Cousins, A unified approach to the classical statistical analysis of small signals, Phys. Rev. D 57 (1998) 3873 [physics/9711021] [INSPIRE].
  28. [28]
    Super-Kamiokande collaboration, A measurement of atmospheric neutrino oscillation parameters by Super-Kamiokande I, Phys. Rev. D 71 (2005) 112005 [hep-ex/0501064] [INSPIRE].

Copyright information

© The Author(s) 2019

Authors and Affiliations

  1. 1.Department of PhysicsUniversity of Illinois at ChicagoChicagoU.S.A.
  2. 2.Physics Division, National Center for Theoretical SciencesHsinchuTaiwan
  3. 3.Department of Physics and AstronomyUniversity of Hawaii at ManoaHonoluluU.S.A.
  4. 4.Kavli IPMU (WPI), UTIAS, The University of TokyoKashiwaJapan

Personalised recommendations