AUTHORS: S. Stoica
(a), H.V. Klapdor-Kleingrothaus (b)
a) Department of Theoretical Physics, National Institute of Physics and
Nuclear Engineering,
P.O. Box MG-6, 76900-Bucharest, Romania
b) Max-Planck Institut fuer Kernphysik, W-6900 Heidelberg, Germany
|
|
ABSTRACT:
We make a systematic study of the two-neutrino and neutrinoless
double-beta decay matrix elements (ME) for several nuclei of experimental
interest.
The calculations are performed with four different quasi random phase
approximation QRPA-based methods (i.e. the proton-neutron QRPA,
the renormalized proton-neutron QRPA, the full-RQRPA,
second-QRPA) and a critical analysis of the results is presented.
A better stability against the change of
the s.p. basis used and a good fulfillment
of the Ikeda Sum Rule allow to reduce the uncertainties
in the values of the neutrinoless ME predicted by the QRPA-based methods
to about 50% from their magnitude. Taking the
most recent experimental limits for the neutrinoless half-lives,
we deduce new upper limits for the neutrino masses. The recent claim of
the
experimental evidence for the neutrinoless double-beta decay mode is also
discussed.
Finally, for each nucleus scales are estimated for the
neutrinoless double-beta decay half-lives that the experiments should
reach for exploring neutrino masses around 0.1 eV. This
might guide the experimentalists in planing their set-ups.
1) Critical view on double-beta decay matrix elements within QRPA-based
methods,S. Stoica and H.V. Klapdor-Kleingrothaus, Nucl. Phys. {\bf A 694}
(2001) 269.\\
2) Evidence for neutrinoless double beta decay, H.V.
Klapdor-Kleingrothaus,
A. Dietz, H.I. Harvey and I.V. Krivosheina, Mod. Phys. Lett A 16 (2001)
2409.
back
|