Search for Cold Dark Matter and Solar Neutrinos with GENIUS and GENIUS-TF

The new project GENIUS will cover a wide range of the parameter space of predictions of SUSY for neutralinos as cold dark matter. Further it has the potential to be a real-time detector for low-energy (pp and 7Be) solar neutrinos. A GENIUS Test Facility has just been funded and will come into operation by end of 2002.Comment: 4 pages, revtex, 3 figures, Talk was presented at International School on Nuclear Physics, 23rd Course: Neutrinos in Astro, Particle and Nuclear Physics, Erice, September 18 - 26, 2001, Publ. in Progress in Particle and Nuclear Physics, Vol. 48 (2002) 283 - 286, Home Page of Heidelberg Non-Accelerator Particle Physics Group: http://www.mpi-hd.mpg.de/non_acc

First Evidence for Neutrinoless Double Beta Decay

Double beta decay is indispensable to solve the question of the neutrino mass matrix together with $\nu$ oscillation experiments. Recent analysis of the most sensitive experiment since nine years - the HEIDELBERG-MOSCOW experiment in Gran-Sasso - yields a first indication for the neutrinoless decay mode. This result is the first evidence for lepton number violation and proves the neutrino to be a Majorana particle. We give the present status of the analysis in this report. It excludes several of the neutrino mass scenarios allowed from present neutrino oscillation experiments - only degenerate scenarios and those with inverse mass hierarchy survive. This result allows neutrinos to still play an important role as dark matter in the Universe. To improve the accuracy of the present result, considerably enlarged experiments are required, such as GENIUS. A GENIUS Test Facility has been funded and will come into operation by early 2003.Comment: 16 pages, latex, 10 figures, Talk was presented at Zacatecas Forum in Physics 2002, 11-13 MAY, 2002, Zacatecas, Mexico, eds. M. Kirchbach and D. V. Ahluwalia (2003), and see Home Page of Heidelberg Non-Accelerator Particle Physics Group: http://www.mpi-hd.mpg.de/non_acc

Search for Neutrino Mass and Dark Matter in Underground Experiments

Search for the neutrino mass and for cold dark matter in the Universe are at present two of the most exciting fields of particle physics and cosmology. This lecture will restrict itself on the search for neutralinos as cold dark matter, and for the absolute scale of the masses of neutrinos, which are the favoured hot dark matter candidates.Comment: 20 pages, revtex, 19 figures, Talk was presented at International Sixth School "Non-Accelerator Astroparticle Physics", ICTP, Trieste, Italy, 9-20 July 2001, eds. R.A. Carrigan et al., pp. 148-174, World Scientific, 2002, Home Page of Heidelberg Non-Accelerator Particle Physics Group: http://www.mpi-hd.mpg.de/non_acc

To be or not to Be? - First Evidence for Neutrinoless Double Beta Decay

Double beta decay is indispensable to solve the question of the neutrino mass matrix together with $\nu$ oscillation experiments. Recent analysis of the most sensitive experiment since nine years - the HEIDELBERG-MOSCOW experiment in Gran-Sasso - yields a first indication for the neutrinoless decay mode. This result is the first evidence for lepton number violation and proves the neutrino to be a Majorana particle. We give the present status of the analysis in this report. It excludes several of the neutrino mass scenarios allowed from present neutrino oscillation experiments - only degenerate scenarios and those with inverse mass hierarchy survive. This result allows neutrinos to still play an important role as dark matter in the Universe. To improve the accuracy of the present result, considerably enlarged experiments are required, such as GENIUS. A GENIUS Test Facility has been funded and will come into operation by early 2003.Comment: 16 pages, latex, 10 figures, Talk was presented at International Conference "Neutrinos and Implications for Physics Beyond the Standard Model", Oct. 11-13, 2002, Stony Brook, USA, Proc. (2003) ed. by R. Shrock, also see Home Page of Heidelberg Non-Accelerator Particle Physics Group: http://www.mpi-hd.mpg.de/non_acc

Status of Evidence for Neutrinoless Double Beta Decay, and the Future: GENIUS and GENIUS-TF

The first evidence for neutrinoless double beta decay has been observed in the HEIDELBERG-MOSCOW experiment, which is the most sensitive double beta decay experiment since ten years. This is the first evidence for lepton number violation and proves that the neutrino is a Majorana particle. It further shows that neutrino masses are degenerate. In addition it puts several stringent constraints on other physics beyond the Standard Model. The result from the HEIDELBERG-MOSCOW experiment is consistent with recent results from CMB investigations, with high energy cosmic rays, with the result from the g-2 experiment and with recent theoretical work. It is indirectly supported by the analysis of other Ge double beta experiments. The new project GENIUS will cover a wide range of the parameter space of predictions of SUSY for neutralinos as cold dark matter. Further it has the potential to be a real-time detector for low-energy ($pp$ and $^7$Be) solar neutrinos. A GENIUS Test Facility has come into operation on May 5, 2003. This is the first time that this novel technique for extreme background reduction in search for rare decays is applied under the background conditions of an underground laboratory.Comment: 20 pages, 13 figure

One Year of Evidence for Neutrinoless Double Beta Decay

The present experimental status in the search for neutrinoless double beta decay is reviewed, with emphasis on the first indication for neutrinoless double beta decay found in the HEIDELBERG-MOSCOW experiment, giving first evidence for lepton number violation and a Majorana nature of the neutrinos. Future perspectives of the field are briefly outlined.Comment: 42 pages, latex, 21 figures, To be Published in Indian National Science Academy (INSA) - Special issue: Neutrinos, (2003) eds. D. Indumathi, G. Rajasekaran and M.V.N. Murthy; see also Home Page of Heidelberg Non-Accelerator Particle Physics Group: http://www.mpi-hd.mpg.de/non_acc