Test of the Pauli exclusion principle for nucleons and atomic electrons by accelerator mass spectrometry

Abstract

The Pauli exclusion principle was tested by searching with accelerator mass spectrometry for non-Paulian atoms with three electrons in theK-shell and for non-Paulian nuclei with three protons or three neutrons in the nuclear 1 s_1/2 shell. For non-Paulian atoms of${}^{20}\widetilde{Ne}$ and${}^{36}\widetilde{Ar}$ the following limits have been obtained:$N({}^{20}\widetilde{Ne})/N({}^{20}Ne)< 2 \cdot 10^{ - 21}$ and$N({}^{36}\widetilde{Ar})/N({}^{36}Ar)< 4 \cdot 10^{ - 17}$. For non-Paulian nuclei of${}^5\widetilde{Li}$ and${}^5\widetilde{He}$ with three protons or three neutrons, respectively, in the nuclear 1 s_1/2 shell the following limits have been measured:$N({}^5\widetilde{Li})/N({}^6Li)< 0.8 \cdot 10^{ - 17}$ for a range of proton separation energies of${}^5\widetilde{Li}$ between 0 and 50 MeV and$N({}^5He)/N({}^4He)< 2 \cdot 10^{ - 15}$ for neutron separation energies between 0 and 32 MeV. The result for⁵Li is used to deduce a limit for the probability β²/2 of finding two colliding protons in the symmetric state with respect to exchange to be β²/2<0.5.10⁻³².