Speaker
Description
Neutron to hidden neutron oscillation (n − n') experiments
are one of the several probes for testing the existence of hidden sector worlds [1,
2]. Although hidden states of matter were originally proposed to restore, on a
general picture, the breaking of P and CP symmetries [4], currently they also
correspond to candidates for dark matter [3]. In this work, we present a new
experimental technique with ultra-cold neutrons (UCN) to test n − n' in the range of
intermediate mass splitting. The experiment, which took place at the ILL's PF2
UCN source in 2020, used magnetic fields in the range [50 − 1130] µT to suppress
the degeneracy-lifting energy difference. The preliminary analysis indicated no
presence of n − n' signals, but lead to a new exclusion region of the parameter
space, written as τ_nn 0 > 1 s for |δm| ∈ [2 − 69] × 10 −12 eV (95% C.L.). [1] C.
Abel et al. “A search for neutron to mirror-neutron oscillations using the nEDM
apparatus at PSI”. In: Physics Letters B 812 (2021), p. 135993. doi:
https://doi.org/10.1016/j. physletb.2020.135993. [2] H. Almazán et al. “Searching
for Hidden Neutrons with a Reactor Neutrino Experiment: Constraints from the
STEREO Experiment”. In: Phys. Rev. Lett. 128 (6 Feb. 2022), p. 061801. doi:
10.1103/PhysRevLett.128.061801. [3] R. Foot. “Mirror dark matter: Cosmology,
galaxy structure and direct detection”. In: In-ternational Journal of Modern Physics
A 29.11n12 (2014), p. 1430013. doi: 10 . 1142 / S0217751X14300130. [4] T. D.
Lee and C. N. Yang. “Question of Parity Conservation in Weak Interactions”. In:
Phys. Rev. 104 (1 Oct. 1956), pp. 254–258. doi: 10.1103/PhysRev.104.254.
