Dark matter search by exclusive studies of X-rays following WIMPs nuclear interactions

Abstract

It is shown that weakly interacting massive particles (WIMPs), which are possible cold dark matter candidates, can be studied by exclusive measurements of X-rays following WIMPs nuclear interactions. Inner-shell atomic electrons are ionized through WIMP-nuclear interaction, and then mono-energetic X-rays are emitted when they are filled by outer-shell electrons. The number of inner-shell holes amounts to as large as one per five nuclear recoils for K-shell and several per recoil for L-shell in the case of medium heavy target nuclei interacting with 100-300 GeV WIMPs. Then the K and L X-ray peaks show up in the 5-50 keV region. Consequently exclusive studies of the X-rays in coincidence with the nuclear recoils and the ionization electrons are found to provide excellent opportunities to detect WIMPs such as the Lightest Super Symmetric Particles (LSP)