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

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 s1/2 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 s1/2 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.