Orateur
Description
The neutron lifetime discrepancy between beam and bottle experiments of 4σ could be interpreted as a possible sign of the neutron decaying into dark particles [1]. If such a decay exists, it could also occur in unstable nuclei with sufficiently low neutron binding energy, a quasi-free neutron decay into a dark matter particle χ; as is the case of 6He with S2n = 975.45keV < mn −mχ [2]. This quasi-free neutron dark decay would be as followed: 6He →4He+n+χ which is the only way to have the emission of a free neutron in the decay of 6He. The SPIRAL1 facility at GANIL was used in June 2021 in order to produce a pure 6He1+ radioactive beam at 25keV to observe an excess of neutrons in the decay of 6He which would be a unique signature for dark matter creation. In this presentation, we report the results of this experiment to set an upper limit for this dark decay mode in 6He.
References
[1] Bartosz Fornal and Benjamin Grinstein. “Dark Matter Interpretation of the Neutron Decay Anomaly” in: Phys. Rev. Lett. 120 (19 May 2018), p. 191801. doi: 10.1103/PhysRevLett.120.191801. url: https://link.aps.org/doi/10.1103/PhysRevLett.120.191801.
[2] M. Pfützner and K. Riisager. “Examining the possibility to observe neutron dark decay in nuclei” in: Phys. Rev. C 97 (4 Apr. 2018), p. 042501. doi: 10.1103/PhysRevC.97.042501. url: https:
//link.aps.org/doi/10.1103/PhysRevC.97.042501.
