Search for β− and β−β− decays of 48Ca Original Research Article

A 48CaCO3 powder sample containing 20.18 g of 48Ca was measured for 797 h with a 400 cm3 low-background HPGe detector. New limits on decays of 48Ca were obtained. For single beta transitions to 48Sc the limits are equal to 0.71×1020 y, 1.1×1020 y, and 0.82×1020 y for transitions to the ground state, excited 5+ and 4+ states, respectively. The new limits on double beta decay to excited states of 48Ti are equal to 0.47×1020 y, 1.1×1020 y, and 0.90×1020 y for transitions to the first 2+, second 2+ and first 0+ excited states, respectively. All limits are given at the 90% CL.