The NEMO 3 experiment results
Autor
Rok
2006
Časopis
Proceedings of Science, PoS(HEP2005)167 (2006) pp. 167/1-167/4
Web
Obsah
The NEMO 3 detector,
which is devoted to searching for neutrinoless double beta decay
(0νββ),
has been operating in the Fréjus Underground Laboratory in France
since February 2003.
Half-lives of the two-neutrino double beta decays
(2νββ)
have been measured for 100Mo and 82Se.
After 389 days of data collection from February 2003 until September 2004,
no evidence for neutrinoless double beta decay was found from
7 kg of 100Mo and 1 kg of 82Se.
The corresponding lower limits for the half-lives are
4.6 × 1023 y at 90% C.L. for 100Mo
and 1.0 × 1023 y at 90% C.L. for 82Se.
Limits for the effective Majorana neutrino mass are
〈mν〉 < 0.66 – 2.81 eV for 100Mo
and 〈mν〉 < 1.75 – 4.86 eV for 82Se.
Radon was the dominant background and is now
strongly suppressed by a radon-trapping facility,
which has been in operation since October 2004.
The expected sensitivity of the NEMO 3 experiment
after five years of data collection will be
T1/20νββ
> 2 × 1024 y at 90% C.L. for 100Mo
and 8.3 × 1023 y at 90% C.L. for 82Se,
corresponding to
〈mν〉 < 0.3 – 1.3 eV and
〈mν〉 < 0.6 – 1.7 eV respectively.
Granty
Projekty
Příklad citace článku:
L. Vála, "The NEMO 3 experiment results", Proceedings of Science, PoS(HEP2005)167 (2006) pp. 167/1-167/4 (2006)