Search for mathrm{U}{(1)}_{L_{mu }-{L}_{tau }} charged dark matter with neutrino telescope

Abstract

We study a simple Dirac fermion dark matter model in mathrm{U}{(1)}_{L_{mu }-{L}_{tau }} theory. The new light gauge boson X plays important roles in both dark matter physics and the explanation for the muon g− 2 anomaly. The observed dark matter relic density is realized by a large mathrm{U}{(1)}_{L_{mu }-{L}_{tau }} charge without introducing a resonance effect of the X boson. As a by-product of the model, characteristic neutrino signatures from sub-GeV dark matter ψ are predicted depending on the mass spectrum. We formulate the analysis of psi overline{psi}to nu overline{nu} , and of psi overline{psi}to XX followed by Xto nu overline{nu} in a model independent way. The energy spectrum of neutrinos in the former process is monochromatic while in the latter process is bowl-shape. We also evaluate sensitivity at Super-Kamiokande and future Hyper-Kamiokande detectors. The analysis is finally applied to the mathrm{U}{(1)}_{L_{mu }-{L}_{tau }} dark matter model.