Detailed studies of {100}$100Mo two neutrino double beta decay in NEMO 3
The full data set of the NEMO 3 experiment has been used to measure the half life of the two neutrino double beta decay of {100}$100Mo to the ground state of {100}$100Ru, $T_{1/2} \left[ 6.81 \pm 0.01\\left( \text{ stat \right) +0.38}_{ 0.40}\left( \text{ syst \right) \right] \times 10^{18}$T1/2=6.81+ 0.01stat 0.40+0.38systx1018 year. The two electron energy sum, single electron energy spectra and distribution of the angle between the electrons are presented with an unprecedented statistics of $5\times 10^5$$5x105 events and a signal to background ratio of \sim 80. Clear evidence for the Single State Dominance model is found for this nuclear transition. Limits on Majoron emitting neutrinoless double beta decay modes with spectral indices of \mathrm{n}=2,3,7$$n=2,3,7, as well as constraints on Lorentz invariance violation and on the bosonic neutrino contribution to the two neutrino double beta decay mode are obtained.
The European Physical Journal C