New experimental limits on the Pauli-forbidden transitions in 12C nuclei obtained with 485 days Borexino data

The Pauli exclusion principle (PEP) has been tested for nucleons (n,p) in 12C with the Borexino detector. The approach consists of a search for γ, n, p, and β± emitted in a non-Paulian transition of 1P3/2-shell nucleons to the filled 1S1/2 shell in nuclei. Due to the extremely low background and the large mass (278 tons) of the Borexino detector, the following most stringent up-to-date experimental bounds on PEP violating transitions of nucleons have been established: τ(12C→12C-tilde+γ)≥5.0x1031 yr, τ(12C→11B-tilde+p)≥8.9x1029 yr, τ(12C→11C-tilde+n)≥3.4x1030 yr, τ(12C→12N-tilde+e-+ν-tildee)≥3.1x1030 yr, and τ(12C→12B-tilde+e++νe)≥2.1x1030 yr, all at 90% C.L. The corresponding upper limits on the relative strengths for the searched non-Paulian electromagnetic, strong and weak transitions have been estimated as δγ2≤2.2x10-57, δN2≤4.1x10-60, and δβ2≤2.1x10-35.