Analysis of ultra low activities to detect solar neutrinos with the radiochemical GALLEX detector
- Max-Planck Institut fuer Kernphysik, D-69029 Heidelberg (Germany)
Solar neutrino detection can probe the state of the solar interior. The flux of pp-neutrinos (from hydrogen fusion: p+p {yields} d+e{sup +}+{nu}e) is firmly predicted from the solar luminosity, any shortage would indicate restmass-mediated {nu}e-disappearance during transit between the solar core and the detector. The expected fluxes of the less abundant but higher energy neutrinos from {sup 8}B and {sup 7}Be depend more sensitively on the details of the solar model. For them, the observation of a deficit may indicate either incomplete understanding of the stellar interior or new physics through massive neutrinos. The low-threshold gallium detector operated by the GALLEX collaboration in the Gran Sasso underground laboratory (Italy) is sensitive to pp-neutrinos. It succeeded in their detection, constituting the first direct observation of hydrogen fusion inside a star. This became possible through single atom detection, constituting the first direct observation of hydrogen fusion inside a star. This became possible through single atom detection in miniaturized proportional counters with background rates <1 count/month. The GALLEX result can accommodate the pp-neutrinos at full strength. At the same time, it confirms a shortage of the higher energy neutrinos, as seen in the results of the Homestake- and Kamiokande experiments. With the present errors GALLEX constitutes a 2.5 problem for {sup 7}Be neutrinos within the frame of 'astrophysical' solutions. Alternatively, the 'particle physics' solution can consistently explain all available solar neutrino results, leading to a most probable mass scale with the muon-neutrino at approximately 3 meV (milli-eV). However, since the GALLEX results allows the presence of pp and pep neutrinos at full strength, the latter explanation of the data is not enforced.
- OSTI ID:
- 21153681
- Journal Information:
- AIP Conference Proceedings, Vol. 329, Issue 1; Conference: 7. international symposium on resonance ionization spectroscopy, Bernkastel-Kues (Germany), 3-8 Jul 1994; Other Information: DOI: 10.1063/1.47603; (c) 1995 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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