First Evidence for Lepton Number Violation and the Majorana Character of Neutrinos

Details First Evidence for Lepton Number Violation and the Majorana Character of Neutrinos First Evidence for Lepton Number Violation and the Majorana Character of Neutrinos

Apr 2005

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005idm..conf..633k&link_type=abstract

THE IDENTIFICATION OF DARK MATTER. Proceedings of the Fifth International Workshop. Held 6-10 September 2004 in Edinburgh, UK. E

Statistics

Scientific paper

Nuclear double beta decay provides an extraordinarly broad potential to search for beyond-standard-model physics. The occurrence of the neutrinoless decay (0νββ) mode has fundamental consequences: first total lepton number is not conserved, and second, the neutrino is a Majorana particle. Further the effective mass measured allows to put an absolute scale of the neutrino mass spectrum. In addition, double beta experiments yield sharp restrictions also for other beyond standard model physics. These include SUSY models (R-parity breaking and conserving), leptoquarks (leptoquark-Higgs coupling), compositeness, left-right symmetric models (right-handeld W boson mass), test of special relativity and of the equivalence principle in the neutrino sector and others. First evidence for neutrinoless double beta decay was given in 2001, by the HEIDELBERG-MOSCOW experiment. The HEIDELBERG-MOSCOW experiment is the by far most sensitive 0νββ experiment since more than 10 years. It is operating 11 kg of enriched 76Ge in the GRAN SASSO Underground Laboratory. The analysis of the data taken from 2 August 1990 - 20 May 2003, is presented here. The collected statistics is 71.7 kg y. The background achieved in the energy region of the Q value for double beta decay is 0.11 events/kg y keV. The two-neutrino accompanied half-life is determined on the basis of more than 100 000 events to be (1.74.{- 0.16}{+ 0.18}) × 1021 years. The confidence level for the neutrinoless signal has been improved to a 4.2 σ level. The half-life is T1/20ν = (1.19{- 0.23}{+ 0.37}) × 1025 years. The effective neutrino mass deduced is (0.2 - 0.6) eV (99.73% c.l.), with the consequence that neutrinos have degenerate masses. The sharp boundaries for other beyond SM physics, mentioned above, are comfortably competitive to corresponding results from high-energy accelerators like TEVATRON, HERA, etc.

Affiliated with

Also associated with

No associations

Rating

First Evidence for Lepton Number Violation and the Majorana Character of Neutrinos does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with First Evidence for Lepton Number Violation and the Majorana Character of Neutrinos, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and First Evidence for Lepton Number Violation and the Majorana Character of Neutrinos will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-976111