|La physique dans tous ses états|
|Date||March 11 > 11, 2023 - 11h30|
|Location||GANIL, room 105|
by Marius Le Joubioux
The neutron lifetime discrepancy between beam and bottle experiments of 4σ could be interpreted as a possible sign of the neutron into dark particles . 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 . 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 (preliminary) results of this experiment to set an upper limit for this dark decay mode in 6He.
 Bartosz Fornal and Benjam ́ ın 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.
 M. Pf ̈ utzner 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.