Electron Events From The Scattering With Solar Neutrinos In The Search Of KeV Scale Sterile Neutrino Dark Matter

Dark matter is a main constituent of our universe, its nature puzzles the world’s most intelligent scientists. Among its candidates keV scale sterile neutrino is a popular one.It has been showed that keV scale sterile neutrino dark matter vs is possible to be detected in β decay experiment using radioactive sources such as3H or106Ru. The signals of this dark matter candidate are mono-energetic electrons produced in neutrino capture process vs+N’→N+e-. These electrons have energy greater than the maximum energy of the electrons produced in the associated decay process N’→N+e-+ve. Hence, signal electron events are well beyond the end point of the β decay spectrum and are not polluted by the β decay process. Another possible background, which is a potential threat to the detection of vs dark matter, is the electron event produced by the scattering of solar neutrinos with electrons in target matter. In this article we study in detail this possible background and discuss its implication to the detection of keV scale sterile neutrino dark matter. In particular, bound state features of electrons in Ru atom are considered in care in the scattering process when the kinetic energy of final electron is the same order of magnitude of the binding energy.