High sensitivity 2β decay study of 116Cd and 100Mo with the BOREXINO counting test facility (CAMEO project)

Abstract

The unique features (super-low background and large sensitive volume) of the CTF and BOREXINO set ups are used in the CAMEO project for a high sensitivity study of 100Mo and 116Cd neutrinoless 2β decay. Pilot measurements with 116Cd and Monte Carlo simulations show that the sensitivity of the CAMEO experiment (in terms of the half-life limit for 0ν2β decay) is ≈4×1024 yr with a 1 kg source of 100Mo and ≈1026 yr with ≈100 kg of enriched 116CdWO4 crystals placed in the liquid scintillator of the CTF. The last value corresponds to a limit on the neutrino mass of mν, ≤ 0.06 eV. Similarly with 1000 kg of 116CdWO4 crystals located in the BOREXINO apparatus the neutrino mass limit can be pushed down to mν ≤ 0.02 eV.