First Measurement of the He3+He3-->He4+2p Cross Section down to the Lower Edge of the Solar Gamow Peak

Abstract

We give the LUNA results on the cross section measurement of a key reaction of the proton-proton chain strongly affecting the calculated neutrino luminosity from the Sun: He3+He3-->He4+2p. Due to the cosmic ray suppression provided by the Gran Sasso underground laboratory it has been possible to measure the cross section down to the lower edge of the solar Gamow peak, i.e. as low as 16.5 keV centre of mass energy. The data clearly show the cross section increase due to the electron screening effect but they do not exhibit any evidence for a narrow resonance suggested to explain the observed solar neutrino flux.

5 pages, RevTeX, and 2 figures in PostScript Submitted for publication

References in corpus (1)

• The Cross Section of 3He(3He,2p)4He measured at Solar Energies

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