The Pauli exclusion principle (PEP) has been tested for nucleons (n,p) in 12C and 16O nuclei, using the results of background measurements with the prototype of the Borexino detector, the Counting Test Facility (CTF). The approach consisted of a search for γ, n, p and/or α's emitted in a non-Paulian transition of 1P- shell nucleons to the filled 1S 1/2 shell in nuclei. Similarly, the Pauli-forbidden β± decay processes were searched for. Due to the extremely low background and the large mass (4.2 tons) of the CTF detector, the following most stringent up-to-date experimental bounds on PEP violating transitions of nucleons have been established: τ(12C → 12C̃ + γ) > 2.1 · 1027 y, τ( 12C → 11B̃ + p) > 5.0 · 10 26 y, τ(12C(16O) → 11C̃(15Õ) + n) > 3.7 · 10 26 y, τ(12C → 8B̃e + α) > 6.1 · 1023 y, τ(12C → 12Ñ + e- + ν̃e) > 7.6 · 10 27 y and τ(12C → 12B̃ + e + + νe) > 7.7 · 1027 y, all at 90 % C.L.
All Science Journal Classification (ASJC) codes
- Engineering (miscellaneous)
- Physics and Astronomy (miscellaneous)