Limits on the Existence of sub-MeV Sterile Neutrinos from the Decay of $^7$Be in Superconducting Quantum Sensors

S. Friedrich , G.B. Kim , C. Bray , R. Cantor , J. Dilling , S. Fretwell , J.A. Hall , A. Lennarz , V. Lordi , P. Machule , D. Mckeen , X. Mougeot (1) , F. Ponce , C. Ruiz , A. Samanta , W.K. Warburton , K.G. Leach

1 LNHB (CEA, LIST) - Laboratoire National Henri Becquerel (CEA, LIST)

Sterile neutrinos are natural extensions to the standard model of particle physics and provide a possible portal to the dark sector. We report a new search for the existence of sub-MeV sterile neutrinos using the decay-momentum reconstruction technique in the decay of Be7. The experiment measures the total energy of the Li7 daughter atom from the electron capture decay of Be7 implanted into sensitive superconducting tunnel junction (STJ) quantum sensors. This first experiment presents data from a single STJ operated at a low count rate for a net total of 28 days, and provides exclusion limits on sterile neutrinos in the mass range from 100 to 850 keV that improve upon previous work by up to an order of magnitude.

Mots clés: Elementary Particles and Fields; neutrino: sterile; electron: capture; superconductivity; beryllium; lithium; S077A00

Domaines: Physique Nucléaire Expérimentale [nucl-ex]; Physique des Hautes Energies - Expérience [hep-ex]; Physique Générale [physics.gen-ph]

S. Friedrich, G.B. Kim, C. Bray, R. Cantor, J. Dilling, et al.. Limits on the Existence of sub-MeV Sterile Neutrinos from the Decay of $^7$Be in Superconducting Quantum Sensors. Physical Review Letters, 2021, 126 (2), pp.021803. ⟨10.1103/PhysRevLett.126.021803⟩. ⟨hal-02999498⟩