1210.1043 (R. Horvat et al.)

Using HPGe detector for a solar hidden-photons search    [PDF]

R. Horvat, D. Kekez, M. Krcmar, Z. Krecak, A. Ljubicic

In this paper we report on the results of our search for photons from a U(1) gauge factor in the hidden sector of the full theory, by observing the single spectrum in a HPGe detector arising as a result of the photoelectric-like absorption of hidden photons emitted from the Sun on germanium atoms inside the detector. The main ingredient of the theory used in our analysis, a severely constrained kinetic mixing from the two U(1) gauge factors and massive hidden photons, leads to both photon into hidden states oscillations and to a minuscule coupling of hidden photons to visible matter, of which the latter our experimental setup has been designed to observe. On a theoretical side, full account was taken of the effects of refraction and damping of photons while propagating in the Sun's interior. We exclude hidden photons with kinetic couplings chi > (1.5x10^{-6}-2.6x10^{-11}) for the mass region 1.7x10^{-4} eV < m_\gamma' < 3.4 eV. Our constraints on the mixing parameter chi at sub-eV hidden-photon masses prove even slightly better than those obtained recently by the ALPS collaboration and by using data from the CAST experiment as well.

View original: http://arxiv.org/abs/1210.1043