Search for 2β processes in 64Zn with the help of ZnWO4 crystal scintillator

Double beta processes in 64Zn were searched for with the help of a low background ZnWO4 crystal scintillator (mass of 117 g) at the Gran Sasso National Laboratories of the INFN. Total time of measurements was 1902 h. New improved half-life limits on different modes of double electron capture and electron capture with positron emission were established as: T1/22ν2K⩾6.2×1018yr, T1/20ν2K⩾4.0×1018yr, T1/20ν2ε⩾3.4×1018yr, T1/22νεβ+⩾2.1×1020yr, and T1/20νεβ+⩾2.2×1020yr, all at 90% C.L.