Neutrinoless Double Beta Decay: 2015 Review

Figure 12

Bounds on the mixing between the electron neutrino and a single heavy neutrino from the combination of bounds obtained with Ge experiments [77] using the representation introduced in [191]. The bands correspond to the uncertainties discussed in the text. The dashed contours indicate the mass regions excluded by some of the accelerator experiments considered in [105]: CHARM (90% CL, [192]), DELPHI (95% CL, [193]), PS 191 (90% CL, [194]), and TRIUMF (90% CL, [195, 196]). The continuous contour indicates the expected probed region by the new proposed SHiP experiment at the CERN SPS [118]. Figure from [118].