The potential of large germanium detector arrays for solar-axion searches utilizing the axio-electric effect for detection

Abstract

The sensitivities of large arrays of low-background germanium detectors for solar axion searches are investigated in the context of three coupling scenarios. A search was made for the 14.4-keV axion branch from the M1-transition in the thermally excited 57Fe in the solar core in 80 kgd of data from the IGEX Dark Matter experiment published earlier. In one scenario, the direct couplings of axions to hadrons and to electrons were assumed to be in the range of Peccei-Quinn (PQ) scale, 3x105 GeV < fPQ < 7x105 GeV. This scenario is excluded by the IGEX data. In a second case, at the same PQ scale, coupling to photons and to electrons are suppressed. The IGEX data partially excludes this scenario depending on the degree of suppression. In the third case, the PQ-scale for all couplings is assumed to be in the range: 3x106 GeV< fPQ <7x106 GeV. Detection rates in Ge for all three scenarios are presented.