Improved limits for natural a radioactivity of tungsten with a CaWO4 scintillating bolometer

An experiment has been carried out at the Canfranc Underground Laboratory with a 54 g CaWO4 scintillating bolometer in the frame of the ROSEBUD (Rare Objects SEarch with Bolometers UndergrounD) Collaboration. This detector has been developed in order to achieve a good particle discrimination capability by means of the simultaneous detection of light and heat with the goal of rejecting background in dark matter search. This Letter reports, as a byproduct of such development, improved limits on the lifetime for a decaying tungsten isotopes. (C) 2003 Elsevier Science B.V. All rights reserved.