New results of 116Cd double beta decay study with 116CdWO4 scintillators

A new phase of 116Cd double beta decay experiment is in progress in the Solotvina Underground Laboratory. Four enriched 116CdWO4 scintillators with total mass 339 g are used in a set up, whose active shield is made of 15 natural CdWO4 crystals (20.6 kg). The background rate in the energy interval 2.5-3.2 MeV is 0.03 counts/y*kg*keV. The half-life for 2-neutrino 2-beta decay of 116Cd is measured as T{1/2}(2-neutrino) = [2.6+-0.1(stat)-0.4+0.7}(syst)]*10**19 y. The T{1/2} limits for neutrinoless 2-beta decay of 116Cd are set as T{1/2} >= 0.7(2.5)*10**23 y at 90%(68%) C.L. for transition to ground state of 116Sn, while for decays to the first 2+ and second 0+ excited levels of 116Sn as T{1/2}>=1.3(4.8)*10**22 y and >=0.7(2.4)*10**22 y with 90%(68%) C.L., respectively. For 0-neutrino 2-beta decay with emission of one or two Majorons, the limits are T{1/2}(0-neutrino M1) >=3.7(5.8)*10**21 y and T{1/2}(0-neutrino M2)>=5.9(9.4)*10**20 y at 90%(68%) C.L. Restrictions on the value of the neutrino mass, right-handed admixtures in the weak interaction, and the neutrino-Majoron coupling constant are derived as: m(neutrino)<=2.6(1.4) eV, eta <=3.9*10**-8, lambda <=3.4*10**-6, and g{M}<= 12(9.5)*10**-5 at 90%(68%) C.L., respectively.Comment: 28 pages, 9 figures (LaTeX). Phys. Rev. C (in press

EURECA – setting the scene for scintillators

voir fichier complet des proceedingsInternational audienceEURECA (European Underground Rare Event Calorimeter Array) will be an astro-particle physics facility aiming to directly detect galactic dark matter. TheLaboratoire Souterrain de Modane has been selected as host laboratory. TheEURECA collaboration concentrates effort on cryogenic detector research inEurope into a single facility by bringing together colleagues from CRESST,EDELWEISS, ROSEBUD and additional new member institutes. EURECA will use atarget mass of up to one ton for exploring WIMP-nucleon scalar scattering crosssections in the region of 10 −9 – 10 −10 picobarn. A major advantage of EURECAis the planned use of more than just one target material (multi targetexperiment for WIMP identification)

Development of CdWO4 Crystal Scintillators from Enriched Isotopes for 2β-Decay Experiments

Cadmium tungstate crystal scintillators enriched in 106Cd (106CdWO4) and 116Cd (116CdWO4) have been developed to search for 2β-decay of 106Cd and 116Cd

EURECA - THE FUTURE OF CRYOGENIC DARK MATTER DETECTION IN EUROPE

EURECA (European Underground Rare Event Calorimeter Array) is an astro-particle physics facility aiming to directly detect galactic dark matter. The Laboratoire Souterrain de Modane has been selected as host laboratory. The EURECA collaboration unites CRESST, EDELWEISS and the Spanish-French experiment ROSEBUD, thus concentrating and focussing effort on cryogenic detector research in Europe into a single facility. EURECA will use a target mass of up to one ton, enough to explore WIMP - nucleon scalar scattering cross sections in the region of 10-9 - 10-10 picobarn. A major advantage of EURECA is the planned use of more than just one target material (multi target experiment for WIMP identification). © EAS, EDP Sciences 2009