Improved Limits on β[sup –] and β[sup –]β[sup –] Decays of [sup 48]Ca.

New limits on [sup 48]Caβ[sup –] and β[sup –]β[sup –] decays to excited states of [sup 48]Ti have been obtained using a 400cm[sup 3] low-background HPGe detector and an external source of 24.558g enriched CaF[sub 2] powder (9.822g of [sup 48]Ca). The limits for β[sup –] decay to the 6[sup +] ground state and excited 5[sup +] and 4[sup +] states in [sup 48]Sc are 1.6×10[sup 20] yr, 2.5×10[sup 20] yr, and 1.9×10[sup 20] yr at the 90% confidence level. For the β[sup –]β[sup –] decay to [sup 48]Ti, the limits to the first 2[sup +], second 2[sup +], and first 0[sup +] excited states are 1.8×10[sup 20] yr, 1.5×10[sup 20] yr, and 1.5×10[sup 20] yr, again at the 90% confidence level. © 2002 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]