NEMO 3 double beta decay experiment: latest results

Abstract

The double beta decay experiment NEMO~3 has been taking data since February 2003. The aim of this experiment is to search for neutrinoless decay and investigate two neutrino double beta decay in seven different enriched isotopes (${}^{100}$Mo,${}^{82}$Se, ${}^{48}$Ca, ${}^{96}$Zr, ${}^{116}$Cd, ${}^{130}$Te and ${}^{150}$Nd). After analysis of the data corresponding to 693 days, no evidence for $0\nu \beta \beta$ decay in ${}^{100}$Mo and ${}^{82}$Se was found. The half-life limits at 90% C.L. are $5.8\cdot 10^{23}$ y and $2.1\cdot 10^{23}$ y, respectively. Using $\sim$ 940 days of data, preliminary results were obtained for ${}^{48}$Ca, ${}^{96}$Zr and ${}^{150}$Nd. For two neutrino decay half-life values were measured, $T_{1/2}{(}^{48}\mathrm{Ca})=[4.4_{-0.4}^{+0.5}(stat)\pm 0.4(syst)]\cdot 10^{19}$ y, $T_{1/2}{(}^{96}\mathrm{Zr})=[2.3\pm 0.2(stat)\pm 0.3(syst)]\cdot 10^{19}$ y and $T_{1/2}{(}^{150}\mathrm{Nd})=[9.2_{-0.22}^{+0.25}(stat)\pm 0.62(syst)]\cdot 10^{18}$ y. Also for $0\nu \beta \beta$ decay the following limits at 90% C.L. were obtained, $>1.3\cdot 10^{22}$ y for ${}^{48}$Ca, $>8.6\cdot 10^{21}$ y for ${}^{96}$Zr and > 1.8 \cdot 10^{22}$yfor$^{150}$Nd.

11 pages included 8 figures and 3 tables, Invited talk at the CISPN ("Columbia Int. Symp. on Neutrino Physics"; Columbia, USA, May 15-17, 2008) and at the 2nd Int. Conf. NPAE-2008 (Kyiv, Ukraine, June 9-15, 2008)

References in corpus (4)

• Anatomy of nuclear matrix elements for neutrinoless double-beta decay
• The influence of pairing on the nuclear matrix elements of the neutrinoless double beta decays
• Nuclear matrix elements of neutrinoless double beta decay with improved short-range correlations
• Measurement of double beta decay of 100Mo to excited states in the NEMO 3 experiment