CUORE/Cuoricino at LBNL and LLNL

The Search for Neutrinoless Double-Beta Decay

Double-beta decays with 2 neutrinos (2νββ) are allowed processes, although has a very long lifetime, longer than 10²¹ years for ¹³⁰Te measured from geochemical data. Recent result (as of January 2005) from Cuoricino puts a lower limit on the lifetime for the neutrino-less double-beta decay for ¹³⁰Te at 1.8x10²⁴ years at 90% C.L. with the corresponding neutrino mass ranges between 0.2 to 1.1 eV. With CUORE, we hope to reach limit of greater than 10²⁶ years. The energy resolution at the no-neutrino double-beta peak of 2.529 MeV is expected to be about 5 keV FWHM.

Cuoricino consists of 11-planes of four 5x5x5-cm³ crystals and two planes of nine 3x3x6-cm³ crystals of TeO₂ for total mass of 40-kg which serve both as a source of double-beta decay and the detector. The crystals are kept at cryogenic temperatures of 10-mK, and temperature rise in the crystals from nuclear events are measured using thermistors produced by Prof. Haller et al. from Berkeley. CUORE will be scaled up to roughly 1-ton, segmented into 1000-channels.